Switchboard, from NRDC › Gina Solomon's Blog

The Health Toll of Climate Change in 2005 and 2011

2011-12-08T17:45:05Z

Gina Solomon, Senior Scientist, San Francisco

As a health professional, I knew that disasters could have devastating impacts on the physical health and psychological well-being of the people who lived through them. But it was only when I went to New Orleans after Hurricane Katrina that I experienced the health toll of a disaster first-hand. People suffered terribly from medical conditions caused or exacerbated by their experiences in the hurricane. Some symptoms were physical – cough, wheezing, and sinus symptoms from the rampant airborne mold. Other symptoms were physical and psychological – anxiety and depression, insomnia and post-traumatic stress disorder. In the months and years after Katrina, serious mental illness among New Orleans residents spiked. Mortality levels climbed from many causes, murder and suicide included.

In 2011 there was no Katrina, but this past year was a blockbuster for extreme weather. There were at least 2,941 weather records broken across the country, including extreme heat, heavy precipitation, and wildfire. Today, NRDC released a new, online extreme weather mapping tool. It lets users track the impacts of extreme weather in 2011, explore how climate change increases risks, and learn how best to protect themselves and their communities from extreme weather events. The bottom line: climate change is affecting our lives and our health right now.

I can’t help but think of how these extreme-weather events take a toll on our health. The most serious impacts, of course, are deaths, which are spotlighted in the media. Unfortunately, the health toll doesn’t stop there. My colleagues and I recently published a study showing that six climate related events in the U.S. within the last decade carried a health toll of over $14 billion dollars, including deaths, hospitalizations, emergency room visits, and outpatient visits. Although anyone can suffer from these health threats, some are especially vulnerable.

Consider the 370,000 Americans with kidney failure who undergo dialysis on a thrice-weekly basis. Without treatment, without the electricity and water and access to a dialysis center they need, they can die within a few days. The emergency instructions currently provided for them don’t inspire much confidence:

Stay at home unless you are hurt.

Begin a survival diet - 2 cups fluid per 24 hours, no fresh fruit or vegetables.

Wait at home for instructions and details about your dialysis clinic on television, radio, messenger or phone.

If you must go to a shelter, tell the person in charge about your special needs.

We need to start preparing now to help people with kidney failure so that they don’t die or become gravely ill during hurricanes, blizzards and wildfires, especially as climate change makes these disasters more frequent and severe.

Likewise, those 1 million Americans with respiratory problems who depend on oxygen therapy to survive, almost all rely on electric-powered oxygen concentrators that extract oxygen from the air and supply it through a tube at high concentrations. This August, during Hurricane Irene, a friend spent the storm with her oxygen-dependent aunt near the shores of Coney Island, on New York City’s waterfront. Had the power gone out in my friend’s apartment, it would have been an inconvenience. But for her aunt, it might have meant life or death. Luckily, the electricity stayed on. And her aunt had several tanks of oxygen for back-up. But in other places far more devastated by the storm, the power was out for as long as a week. And roads were impassable. In situations such as these, how will we take care of our most vulnerable?

I have a three-part prescription. First, on an individual level, people with life-threatening illnesses and their caregivers must prepare for extreme weather events. Information for people on dialysis is available from the National Kidney Foundation. Those who are oxygen-dependent should check out this site. All others with serious medical conditions should discuss emergency plans with their healthcare providers.

Second, on the local, state, regional, and federal level, we need emergency-preparedness programs that anticipate climate change. Right now, only 13 out of 50 states have them. Each dollar invested in this type of planning saves about five dollars down the road. And the savings in heartbreak is immeasurably high. Either way, this kind of preparation is taxpayer money well-spent.

Finally, the time to prepare and act to prevent climate change’s worst impacts is now. That’s not just my position. It’s one that’s shared by the American Medical Association, the country’s largest organization of doctors and medical students; by the American Public Health Association, the world’s oldest and most diverse public health group; and, by a myriad of other medical and public health associations. We need to heed the signals from our environment. People across the country are still suffering from this year’s weather disasters as 2011 draws to a close, just as people in New Orleans are still suffering six years later. We cannot afford many more years like this.

FDA's claims don't add up

2011-11-22T18:01:16Z

Gina Solomon, Senior Scientist, San Francisco

Last night, our recent scientific paper on Gulf seafood safety was featured on Anderson Cooper's 360*. It's a nice piece, and is worth watching, since it highlights the ongoing crisis in the Gulf fisheries, and the ongoing disagreements about seafood safety. But I was distressed to hear FDA's Robert Dickey's statements on the show, He claimed (without any substantiating evidence) that:

1) “The seafood from the Gulf of Mexico is safe to consume for all consumers including pregnant women and children;” and

2) “the amount of seafood that somebody would have to eat would be the equivalent to sixty-three pounds of shrimp, or five pounds of oyster, or nine pounds of fin fish every day for five years before they would exceed levels to be concerned of. That’s how low the residues are in the seafood.”

The FDA's comments are simply not consistent with the reality. Here's the rest of the story:

Reality: FDA only examined what would be safe for an adult. When they did their calculations they looked at what level of contamination would be safe for a 176 pound person. Children are known to be more vulnerable to contaminants in seafood because they eat more per pound of their bodyweight and their developing bodies are more sensitive to harmful contaminants. What’s more, in a pregnant woman, these contaminants can cross the placenta and harm the developing fetus. This increased vulnerability is well known to science, and other agencies require that children be included in safety assessments.

How can FDA claim Gulf seafood is safe for children and pregnant women when they didn’t do the evaluation required by other agencies?

Then there's the jaw-dropping FDA claim that people can eat sixty-three pounds of shrimp, or five pounds of oyster, or nine pounds of fin fish every day for five years before they would exceed levels of concern. Where did that come from?

Reality: FDA generated these numbers based on the same faulty science they used to evaluate the seafood in the first place. Here’s a run-down of the assumptions:

1) These numbers are for adults only and don’t include the special sensitivity of children or the developing fetus.

2) FDA continues to assume that people eat only one kind of seafood at a time, instead of a normal combination of fish, shrimp, and oysters.

3) FDA ignores the cancer causing impact of the most common contaminant from oil - naphthalene - even though it was listed as a carcinogen by the National Toxicology Program.

4) FDA insists the contamination will only stick around for 5 years despite the science from previous oil spills.

5) FDA has says that it is OK for contaminated seafood to cause an extra 10 cancers per million people. For previous oil spills, like the Exxon Valdez, they said it was only OK to have 1 excess cancer per million people.

These faulty assumptions mean that FDA’s calculations don’t make sense and can’t be used to say that seafood is safe.

Using up-to-date scientific methods to assess seafood safety we found that 53% of the shrimp tested by NOAA and 26% of shrimp tested by FDA could pose a risk to a child in-utero if the mother ate a Gulf shellfish-rich diet that includes 0.6 pounds of (or about 14 jumbo) shrimp per week while she was pregnant and then continues to feed seafood to her kid when they are older - including 0.3 pounds of (about 7 jumbo) shrimp per week. Our calculation assumes that people eat a variety of shellfish including: (adult) - 0.3 pounds of crab and 0.2 pounds of oysters per week (child) – 0.15 pounds of crab and 0.1 pounds of oysters per week.That's a far cry from the 63 pounds of shrimp that FDA claims is safe.

The fact remains that FDA's numbers don't make sense, aren't consistent with current scientific practices, and won't protect the health of pregnant women and children. It wouldn't be hard for FDA to fix their calcuations and set an appropriate limit for contaminants in seafood. We petitioned the agency to do just that. I'm still hoping they'll respond to our petition and do the right thing.

A Family is Biomonitored: What Did They Learn?

2011-11-04T16:12:59Z

Gina Solomon, Senior Scientist, San Francisco

The Martin family lives in Maywood, California, just minutes from Los Angeles. They are dealing with chronic illnesses and a history of lead poisoning. Now they are trying to learn more about what might be affecting their health, and whether the community where they live may be making them sick.

This family received some help and attention from a freelance reporter who just published an important article in California Watch. The story is worth reading, and it’s here.

Here’s the setting for the Martin family’s story: “Starting a few blocks from their home, nearly 2,000 factories churn out Southern California’s hot dogs, pesticides, patio furniture and other products. Trucks rumble off the I-710 freeway into sprawling freight rail yards. Odors of rotting animal carcasses waft through the family’s windows on hot summer nights.”

In technical jargon, it’s called “cumulative exposure” – the combined pollution from living near freeways, electroplating shops, battery smelters, rendering plants, plastics molding facilities, and other industrial facilities. The pollution from these facilities interacts in complex ways in the body, and is exacerbated by other factors such as drinking water contamination, nutrition, stress, and genetic susceptibility. It’s hard to quantify these cumulative problems. In fact, scientists still don’t know how to add up all these risks in any kind of logical way.

Today, government agencies quantify the health risks from each industrial polluter separately and in isolation. Other agencies set allowable standards for drinking water pollution. Nobody adds it all together. Yet someone should, because it’s abundantly clear that some communities are suffering disproportionately from illnesses and from an aggregation of local hazards that shouldn’t be overlooked. Some such communities are experiencing disease clusters, which I have blogged about here.

The Martins are unusual because they had their blood tested for contaminants. The testing identified a number of toxic metals at elevated levels in the blood of several family members, including:

Vanadium, which is used to make steel; the health effects are poorly understood;
Mercury, a known neurotoxin that interferes with normal development of the brain, language acquisition, and IQ;
Arsenic, which in its inorganic form is a known carcinogen;
Manganese, which is used in steel and other alloys, and causes neurological damage.

When I reviewed the testing results for this family, I couldn’t definitively link any of these numbers to the pollution they breathe or the water they shower in and drink. The problem with biomonitoring is that there’s no signature on the contaminants identifying their origin. It was impossible to know for sure if these contaminants came from any local facility, or from some other unidentified source. Biomonitoring is limited in that way – nobody has yet figured out how to ‘fingerprint’ environmental contaminants, so scientists can measure these pollutants in people, but never know where they came from.

In addition, without additional expensive testing, it’s impossible to know if the elevated arsenic levels are a toxic or non-toxic form of arsenic (the latter, organic arsenicals, occur naturally in seafood). Similarly, it isn’t possible without additional investigation to determine if the mercury is organic (and therefore probably from fish consumption) or inorganic and potentially from other nearby sources. Both forms of mercury are toxic, but the likely sources differ. Interestingly, the Martin family apparently eats fish very rarely.

As with many people who have been biomonitored, the Martins ended up with more questions than when they started. That’s why biomonitoring is still mostly reserved for research studies to identify patterns of exposure in populations rather than in individuals. But biomonitoring is expanding and more people are demanding testing every day. In the future, these methods will expand significantly, to allow development of an exposure profile for individuals. I have blogged previously about the future of biomonitoring here.

The main thing the Martin family’s story shows is that people living in communities affected by pollution and chemicals are demanding information and answers. Meanwhile the agencies are still struggling to find ways to even quantify the cumulative effects of all the environmental stressors in our lives. A few years ago, the National Academies of Science issued an important report, telling the Environmental Protection Agency to figure out a strategy for addressing cumulative exposures. The State of California is struggling to develop these methods (read more about that effort here), but the U.S. EPA needs to move forward on this important recommendation. Communities such as Maywood are in the bull’s eye of industrial pollution, and people’s health needs to be protected.

It's National Seafood Month and the FDA Must Protect Consumers from Contaminants in Seafood

2011-10-12T12:00:00Z

Gina Solomon, Senior Scientist, San Francisco

October is National Seafood Month, so it’s a good time to reflect on seafood safety. I have been raising concerns for years about this issue, since it’s an important and delicate balancing act for doctors and consumers. On the one hand, many types of seafood are a low-fat source of omega-3 fatty acids and healthy protein. As a physician, I like to recommend seafood to pregnant women, children, and others. But on the other hand, some types of seafood can contain unhealthy doses of mercury, PCBs, and other contaminants.

Fortunately there are types of fish that are generally low in mercury, but high in omega-3’s. A handy wallet card and seafood guide to help pick lower mercury seafood is here. But mercury isn’t the only problem I’m thinking about during National Seafood Month.

In the aftermath of the BP oil spill in the Gulf of Mexico, there were serious concerns about the safety of Gulf seafood. Crude oil contains chemicals called PAHs (polycyclic aromatic hydrocarbons), which are also found in soot, cigarette smoke, and diesel exhaust. PAHs can cause cancer, and studies of newborns have shown that prenatal exposure to PAHs is also linked to neurological and developmental delays. Unfortunately certain types of seafood – especially shellfish such as oysters and shrimp – can accumulate PAHs and become toxic to consumers. After the oil spill, my colleagues and I evaluated the FDA’s safety assessment that justified reopening the Gulf to fishing, and we raised numerous concerns, detailed in earlier blogs here, and here. We reached out to the FDA repeatedly to encourage the Agency to fix the flaws in the seafood safety assessment, but our efforts were ignored.

This week, the scientific journal Environmental Health Perspectives is publishing our critique of the FDA Gulf seafood safety assessment. In this peer-reviewed scientific study, we applied currently accepted risk assessment calculations to the situation in the Gulf, and came to very different conclusions than the FDA. In fact, we found that the cancer risk associated with Gulf seafood consumption was up to 10,000 times higher than the risk calculated by the FDA. That’s because the FDA assumed that all consumers were large adults (weighing 176 pounds) and ignored smaller women and children who are more vulnerable; the FDA also assumed that people eat relatively little seafood, and that they never eat oysters, shrimp, and fish all in the same week; FDA also assumed that all of the contamination in the Gulf will have disappeared within 5 years, and that the most common of the PAH chemicals was not carcinogenic (even though the National Toxicology Program says it is). Our findings suggest that the decision to open some areas of the Gulf to fishing may have been premature, and that pregnant women should still exercise caution about Gulf shellfish. My colleague and co-author Miriam Rotkin-Ellman’s blog provides additional information about our study.

The most disturbing thing about this newly-published study on the flawed FDA seafood safety assessment isn’t just the implications for Gulf seafood. The real problem is that the FDA is not putting consumer safety first. In fact, the FDA’s response to our journal article expressed the concern that our calculations “would unnecessarily exclude many food groups from consumers.” In contrast, the European Food Safety Authority has taken action to restrict the allowable levels of PAHs in numerous foods including seafood, in an effort to protect public health. That’s what the FDA needs to do too. Instead, the FDA is failing to protect consumers from PAHs, and also from many other threats, including:

Mercury in seafood, which is well-recognized to damage the brain. FDA's website calls out only a few types of fish with the highest mercury levels, and gives especially confusing guidance for children. Worse still, the agency does utterly inadequate monitoring for mercury in seafood, basing their recommendations on a few dozen samples of most types of seafood nationwide over the past two decades.
Hormone-disrupting chemicals such as bisphenol A, which can contaminate canned foods (see my colleague Sarah Janssen’s recent blog post for new developments on this).
Antibiotic-resistant ‘super-bugs’ in food, which can lead to major health problems and make lifesaving drugs less effective.

That’s why we’re launching a broader campaign to “Fix FDA”. I hope the FDA will respond quickly to the petition we’re filing today to set a scientifically-justifiable tolerance for PAHs in seafood, and take action to protect consumers. It’s the right thing to do for National Seafood Month.

Time for EPA to Get Moving on Risks of Drinking Water Contaminants

2011-09-29T18:51:25Z

Gina Solomon, Senior Scientist, San Francisco

Anyone who saw the famous movie Erin Brockovich is familiar with hexavalent chromium, or 'hex chrome'; it's the carcinogen that polluted the town water supply in Hinkley, California and triggered the David vs. Goliath fight between sick community members (aided by Erin Brockovich), and PG&E, the polluter.

The real fight raged long after Hollywood moved on to other blockbusters. The list of corporations that are responsible for the nearly 700 toxic waste sites with chromium contamination reads like a Who’s Who of the rich and powerful, including military and military contractors, pesticide companies, leather, plating, utilities, and chemical companies. These polluters successfully spent the past decade using every political maneuver in the book to delay regulations on this chemical and reduce their clean-up costs. As a result, more than a decade after the Erin Brockovich movie, the federal government still has not issued any regulations on hex chrome, including a drinking water standard.

The program at EPA that assesses the toxicity of chemicals showed a sign of life last year, releasing a draft assessment of hex chrome for scientific peer review. Now EPA is under pressure by the chemical industry (the American Chemistry Council) to delay the chromium assessment for several more years. You see, the chemical industry has their own study underway, and they are confident that it will somehow prove that this cancer-causing chemical isn’t so cancer-causing after all.

The polluters made these exact arguments in California over the past few years, but Cal/EPA moved forward and finalized their assessment, concluding that it was irresponsible to continue to delay while some people are drinking this pollution in their water. Now California is poised to become the first state in the nation to have an enforceable drinking water standard that will protect health.

One of the major arguments that industry made in California is worth discussing, since it’s typical of the tactics they use. They argued that hex chrome, when it enters the acidic environment of the stomach, is detoxified through conversion to trivalent chromium (which does not cause cancer). That argument actually has some scientific basis, but there are a couple of small problems: First, infants in the first year of life do not have acidic stomachs, so if there is hex chrome in the water they’re drinking, they won’t effectively detoxify it. Second, what about the millions of Americans who are taking medications to treat gastritis, peptic ulcer disease, or reflux? These medications would make these estimated 40 million people more vulnerable to a carcinogen like hex chrome. The State of California soundly rejected the industry argument, but the American Chemistry Council, undaunted, is polishing the faded argument up again for the EPA.

I wish I could say that the only problem was with hex chrome. In fact, the EPA process is stalled on numerous dangerous contaminants in drinking water, including arsenic, perchlorate, and perchloroethylene (PCE). Attacks from anti-regulatory politicians will hinder EPA’s ability to protect the public from contaminants in the water supply. The EPA shouldn’t let these attacks interfere with the agency’s duty to protect public health.

Today, NRDC sent a letter to EPA Administrator Jackson signed by 35 environmental, environmental justice, and public health groups asking EPA to stick with their schedule and get the assessment finalized on time.

Children Hold Your Breath, Healthy Homes No More

2011-09-22T20:00:45Z

Gina Solomon, Senior Scientist, San Francisco

Successful environmental health programs are on the chopping block in this year's budget. President Obama has proposed major budget cuts to the Centers for Disease Control’s (CDC) National Center for Environmental Health, including asthma prevention programs, funds to track and investigate lead poisoning, and emergency response biomonitoring programs.

Asthma Prevention Programs

The asthma prevention program funding would be cut in half, from about $20 million to $10 million. This is a hugely effective program that dramatically reduces emergency room visits for kids with asthma. Funds in this program allow local agencies to help out when children are admitted to the hospital with asthma attacks. The agencies help parents identify triggers that cause asthma attacks and learn preventative measures to better manage their child's asthma. This program pays for itself many times over by reducing emergency room visits and missed school days among children with asthma. Learn more about this important program here.

It is especially important that asthma funding for the most vulnerable populations is secure as politicians wage war on clean air. A recent study published by one of my colleagues in collaboration with researchers at Mt Sinai Hospital projected that asthma emergency department visits among children in New York City are likely to rise by 7.3 percent in the next decade due to the effects of climate change on ozone smog. The Administration delaying a science-based ozone standard ensures more cases of asthma in children and amplifies the need for the CDC prevention program. Additionally, people that live near certain industries have increased exposure to air pollutants that cause respiratory complications.

Healthy Homes

Healthy Homes funding is being reduced from about $28 million to $15 million. This funding, which is used to track and investigate lead poisoning among children, is being cut in half. It is likely that as a result of this cut, childhood blood lead levels will plateau or increase over the coming years, since sources of lead won’t be identified and addressed quickly enough to protect other children from poisoning.

Children are especially vulnerable to lead poisoning because a growing child’s nervous system can suffer permanent damage from toxic exposure during key periods of brain development. Lead poisoning in children has long been known to causes serious problems, ranging from lowered IQ and learning delays, to behavioral problems, as explained by the American Academy of Child and Adolescent Psychiatry. Learn more about the critical role of lead poisoning prevention programs here.

Biomonitoring

After the Fukushima nuclear disaster in Japan, the CDC deployed teams to measure for radionucleotides downwind, including in the U.S. So it's ironic to see a 40% cut to radionucleotide detection and biomonitoring emergency response funding in the proposed budget. This cut will hamper the CDC in its mission to ensure American safety in the event of an emergency. Learn more here about the emergency response biomonitoring capabilities that will be cut.

Aside from national security concerns, biomonitoring is a crucial piece of the puzzle in evaluating environmental health. I have previously blogged about new advances in biomonitoring science here.

Tracking Disease and the Environment

The CDC also has an important program that tracks numerous health threats to identify trends, geographic differences, and linkages. This ‘Tracking Program’ also provides an important tool for evaluating the effectiveness of environmental regulations. The budget for this program was moved around internally, and there is no longer any funding to support staff to run the program at the CDC. Losing the ability to track important diseases and environmental links will blind the agency to important and emerging health threats.

The President is failing to support his Race to the Top message with his actions. America can be in a Race to the Top and protect American’s health and safety. To do so we must ensure America’s most vulnerable populations are protected. I urge the President to uphold air quality standards and fund critical environmental health programs that help victims of pollution, lead and radiation.

Thanks to Anne McCarthy for assistance with researching and writing this blog.

Waiting for Irene and Remembering Katrina

2011-08-25T22:46:45Z

Gina Solomon, Senior Scientist, San Francisco

Like most people on the East Coast, I’m anxiously watching the approach of Hurricane Irene, a swirling knot of wind and rain taking dead aim at New York City, where I’m currently visiting my family. I had been hoping to fly home to California on Monday morning, but now I’m wondering if that will happen. I’m also wondering about what kind of damage and health threats this hurricane will bring.

Almost precisely six years ago today, I watched anxiously as Hurricane Katrina bore down on the Gulf Coast. After that disaster, I was part of a health response team mobilized to evaluate the environmental damage in New Orleans. I remember entering the flooded city horrified and awed at the destruction that happened there - - cars flipped on their roofs and piled on top of each other, houses obliterated or moved from their foundations, and the chalk marks on homes showing the death toll inside. The photo journal from our research team is here. We investigated the serious health threats from rampant mold, arsenic-laced sediment and soil, and contaminated drinking water. Our reports are available here.

One of the shocking things about the flooding of New Orleans was how predictable it was. The city was well-known to be vulnerable to hurricanes, and the levees were documented to be insufficient to withstand a powerful storm. Yet the failure to adequately prepare – both in the long term by building stronger levees, and in the short term by evacuating people from vulnerable areas – lead to nearly 2,000 deaths, the displacement of about 800,000 people, and an estimated cost of well over $120 billion dollars.

Today, New York City is staring down the barrel of a loaded gun named Irene.

Like New Orleans, New York and nearby areas are also known to be vulnerable to hurricanes, although the region has been lucky and hasn’t been hit with a major hurricane since 1821. Our luck may have just run out. High tide and storm surge could flood the NY subway system and roadways, large parts of Lower Manhattan, and other coastal areas such as Long Island. High winds roaring through the urban canyons of New York propelling flying debris through windows is a really scary thought.

It’s hard to say what will happen when Hurricane Irene hits, and it will certainly look different from the Katrina disaster, but there’s a really high likelihood of over a billion dollars of damage to property, and – unfortunately – many lost lives. But it’s not only New York that’s at risk. A major portion of the Eastern seaboard is in the storm track. To find out if you live in an area vulnerable to flooding along the East Coast, check out these flood vulnerability maps that allow you to search for your local area. Or if you live in New York City, you can check this site to determine your risk. If you live in a flood zone, be prepared to evacuate if you need to. See my colleague Kim Knowlton’s blog for information about how to prepare for the storm.

Climate change is projected to significantly increase the intensity of hurricanes and other storms. We have already seen a record-breaking year in 2011 with major winter storms, tornados in the spring, record-breaking heatwaves this summer, and now a potentially devastating hurricane. Things are so bad that the new “normal” weather is swinging into a pattern of extremes. The climate-related events of 2011 so far bear an estimated price tag of $265 billion, at a time when our nation can ill-afford it.

Our climate is already changing right before our eyes, and it’s not a pretty sight. As a health professional, I am pleading with politicians in Washington DC to take practical steps to deal with climate change…. Before it deals with us.

Mosquito-Borne Disease and Climate Change: Should you use DEET?

2011-08-10T19:29:01Z

Gina Solomon, Senior Scientist, San Francisco

Mosquito and ticks carry a variety of infectious agents, including those that cause malaria, West Nile, Dengue Fever and Lyme disease. NRDC recently launched a new website with climate maps of the United States. One of the maps shows the areas where two key mosquito species are known and projected to live. These two species are the ones that can carry Dengue fever. Dengue (also known as "Breakbone Fever") causes a characteristic triad of high fever, horrible body aches, and a rash. Last year, there was an outbreak in Florida, and there are frequent small outbreaks along the Texas border. Now is the time of year for clinicians in the Southern U.S. To start being alert to possible cases of this disease. Cases are now required to be reported to the Centers for Disease Control and Prevention.

Check out the NRDC Climate Maps, to see if you live in an area that may be vulnerable to Dengue fever - or to any of the other climate-related health threats highlighted on the site. Meanwhile, here are some things you can do:

Wear long-sleeved protective clothing and long pants, especially at dawn or dusk;
Limit outdoor time during dawn and dusk;
Make sure you have window screens on all your windows, and that they don't have holes;
Use insect repellants judiciously to help prevent mosquito bites and thus prevent disease.

Which mosquito repellent should you use?

DEET (N,N-diethyl-meta-toluamide) is the active ingredient in many brands of insect repellants sold in the United States. First approved for public use in 1957, DEET has remained the gold-standard as a topical insect repellant and is available in a variety of formulations including, but not limited to, lotions, gels, sprays, foams, and towelettes designed to be applied directly to the skin or clothing.

Although there is no controversy regarding the efficacy of DEET for preventing insect bites, there have been several case reports associating DEET with seizures in children. One study reviewing alleged DEET- induced encephalopathy and seizures via skin application of DEET in children concluded that repellents containing DEET were not safe and should be avoiding in the young. A very recent study done by an international group of researchers found that DEET inhibits cholinesterase activity, an enzyme necessary for appropriate nervous system function in insects and mammals. Symptoms of cholinesterase inhibition include headache, nausea, convulsion, and in extreme cases, death.

Despite the above, it’s important to note that with proper use, the overall safety record of DEET over the past 50 years has been excellent. There have been 43 reported cases of DEET toxicity, including 17 allergic and cutaneous reactions, 25 with central nervous system symptoms and one case with cardiovascular symptoms. Six deaths have been reported in the setting of DEET, three of them caused by intentional ingestion, one involved a child with a baseline metabolic disorder and two children had reported central nervous system symptoms that occurred after DEET use.

One review that looked at DEET toxicities reported to poison control centers over a four year period concluded that the risk of DEET toxicity was overall low, reported in 0.05-0.1% of users. The American Academy of Pediatrics Committee on Environmental Health recommend DEET use only in children over two months of age, at concentrations limited to 10-30 percent.

Alternatives:

Concerns regarding the toxicity of DEET, especially in pediatric populations have led to the discovery and development of other types of insect repellants. Several alternatives to DEET now exist, the most common of them being Picaridin, Permethrin, and Oil of lemon eucalyptus. The US Centers of Disease Control and Prevention has approved the use of Picaridin and oil of lemon eucalyptus as alternatives to DEET with repellent activity sufficient enough to deter mosquitoes. Permethrin is a pesticide with toxicity that seems to be more significant than DEET, so it should be avoided when possible. Some people can develop allergic reactions or rashes to lemon-eucalyptus oil, and it doesn't repel insects for as long as DEET does.

Overall, if you do need an insect repellent, I'd suggest going either with a low-concentration formulation of DEET (30 percent or less) or with picaridin. Avoid any products that mix sunscreen with DEET, since sunscreen needs to be reapplied frequently to be effective, and is mostly necessary in the middle of the day, whereas DEET does not need to be reapplied very frequently, and it's mostly needed in the mornings and evenings when mosquitoes are most active, so a combined formula makes little practical sense.

I'm a believer in avoiding any unnecessary use of chemicals, but insect repellents have an important role in our world, especially as the climate changes and diseases such as West Nile, Lyme, and even Dengue fever spread into new zones.

Hexavalent Chromium in Drinking Water: Welcome News from California

2011-07-27T17:43:45Z

Gina Solomon, Senior Scientist, San Francisco

Today, the State of California took an important step toward protecting people from cancer-causing chromium in drinking water. After a decade of study, public review, meetings, and scientific analysis, the California Environmental Protection Agency (Cal/EPA) released a final Public Health Goal (PHG) for hexavalent chromium.

Anyone who saw the famous movie Erin Brockovich is familiar with 'hex chrome'; it's the known human carcinogen that polluted the town water supply in Hinkley, California and that resulted in the David vs. Goliath fight between sick community members (aided by Erin Brockovich), and PG&E, the polluter.

The real fight raged long after Hollywood moved on to other blockbusters. Polluters successfully spent the past decade using every political maneuver in the book to delay regulations on this chemical. A couple of years ago, they even unsuccessfully attempted to entirely eliminate the arm of Cal/EPA - the Office of Environmental Health Hazard Assessment (OEHHA) - that was doing the scientific calculations to set the chromium PHG. The repeated delays mean that California is now seven years past a legal deadline for setting a drinking water standard for this chemical.

The health-based level that was announced today - at 0.02 parts per billion (ppb) in drinking water - is not only the most stringent scientific standard in the nation, it's the only such benchmark in the nation. It's really time for the federal government to move forward with their drinking water regulations for this cancer causing chemical.

Today's announcement doesn't mean that the fight is over. Today's health-based level is not a legally enforceable standard. In the next step, the California Department of Public Health must set an enforceable standard (known as a Maximum Contaminant Level, or MCL). This standard must factor in health effects, feasibility of detection, clean-up technologies, and cost. Let's hope this process doesn't take another decade...

At the beginning of this year, I made a New Year's resolution on my blog to do everything possible to get a health-protective, science-based, final PHG in place for this dangerous chemical in 2011. It's great to be able to check one item off that list (thanks to hard work by lots of other people!) But we still need an enforceable standard to assure that everyone in California is protected, and we need a federal standard that will protect vulnerable infants and children nationwide. You'd think that when the science is this clear, the policy would follow, but instead, the fight rages on...

Fear-Mongering, Junk Science, and the Chemical Industry

2011-07-14T04:38:37Z

Gina Solomon, Senior Scientist, San Francisco

On Tuesday, my colleague, Dr. Sarah Janssen, attended a hearing of a California scientific panel that identifies reproductive toxicants. The panel unanimously rejected a chemical industry petition that would have eliminated the National Toxicology Program as an authoritative agency for defining reproductive toxicants in California. This vote was an important win because the industry petition was a bare-faced political attempt to block the listing of bisphenol A (BPA) as a chemical that is “known to cause reproductive harm”. We worked hard to make sure the California panel knew the facts before they voted.

Sharing scientific facts seems like it should be fairly straightforward, but there’s always a cacophony of naysayers trying to dispute scientific findings. Tuesday was no different. Right before the vote, chemical industry reps passed out a blog coincidentally posted that same afternoon by Henry Miller trying to discredit the science on BPA, and attacking NRDC directly. As a physician and scientist who has been working for 15 years to protect children from toxic chemicals and pollution, I was saddened by Henry Miller’s revisionist history of the work of environmental organizations to protect human health. The truth is quite different from the lies presented in Miller’s slanted view from his perch at the ultra-conservative Hoover Institution. And I think it’s important to set the record straight.

First, let’s review the real history of Alar:

In 1989, NRDC released a report revealing that the government was not protecting children from cancer-causing and neurotoxic pesticides on food. One of the 29 chemicals analyzed in the report was Alar, a chemical that was used to force all apples in an orchard to ripen at the same time, thereby increasing the convenience of harvesting the fruit.

Alar was also known to rapidly transform, when heated, into another chemical on the fruit – UDMH (unsymmetric dimethyl hydrazine) – a chemical used in rocket fuel, and subsequently breaks down to dimethylnitrosamine. Both of these chemicals were already known to cause cancer back in the 1980’s and the science has only strengthened since that time. According to the National Toxicology Program’s 12th Report on Carcinogens, UDMH causes angiosarcoma, tumors of the liver, lung, and kidneys, as well as neurofibromas.

In 1989, NRDC used EPA’s own cancer risk numbers to calculate risks to children, and EPA agreed that the risks of this chemical were unreasonable and that the chemical should be withdrawn. Ever since then, the apple industry had done just fine without Alar, and our children have been safer as a result.

More importantly, the National Academy of Sciences reviewed the topic of pesticides and children’s health in response to the NRDC report, and concluded that the government was not adequately protecting kids from dangerous pesticides. As a result, Congress overwhelmingly passed the Food Quality Protection Act, a law that requires that pesticide residues must be controlled on foods to levels that won’t harm children – a novel concept at that time, perhaps, but one that we should all be grateful for!

Fast forward 22 years to today:

Bisphenol A (BPA) is a chemical that has come into widespread use in consumer products, despite the fact that it was originally developed as an estrogenic drug. It leaches out of some of these products, such as baby bottles, sippy cups, and the linings of food cans, and contaminates foods including infant formula. The Centers for Disease Control and Prevention has shown that 95 percent of people in the U.S. have residues of BPA in their bodies. This chemical is known to interfere with human hormones, and has been linked to behavioral changes and developmental alterations in babies. Over 200 peer-reviewed scientific studies have demonstrated harm from BPA. It isn’t just NRDC raising the alarm about this chemical. Major scientific organizations such as the President’s Cancer Panel, and the National Toxicology Program have raised concerns about BPA. Ten U.S. states have joined Canada, the European Union, and China to ban certain uses of BPA for health reasons. So NRDC is far from alone in advocating for controls.

Motives for the attack on NRDC:

A California law, passed by a 2/3 majority of voters in 1986, requires that consumers be warned when they are exposed to chemicals known to cause cancer or reproductive harm – a reasonable request, I’d say. And BPA – a hormone-disrupting chemical that interferes with reproduction and infant development – should be one of the chemicals against which consumers are warned. In fact, the State of California has already initiated the process to list BPA under the law. A listing wouldn’t trigger the blizzard of crazy results that Miller suggests, but could require warnings on products that could result in significant human exposure to BPA, such as BPA-containing baby bottles, and food cans that still contain a BPA liner. This would allow consumers to make informed choices to protect themselves and their families from this chemical. Not surprisingly, the chemical industry is unhappy with the prospect, since BPA brings in multi-billion dollars in chemical sales each year. So yesterday, industry tried (and failed) to get a scientific panel to throw up a roadblock to the BPA listing. Miller’s blog (with the ink barely dry on the page) was handed out in a clear effort to sway the process. Fortunately, nobody was fooled by Miller’s lies, and the strength of the science won out.

In the fight between industry profit and human health, apologists like Miller can spread their lies, but people see through the smoke and know what matters – the health of our children.

Advances in Monitoring Equipment Will Help Communities Keep Tabs on Polluters

2011-06-24T18:41:36Z

Gina Solomon, Senior Scientist, San Francisco

Just recently I wrote a blog on scientific advances in biomonitoring. The advances in exposure science, however, don’t just involve biomonitoring. Microsensor and nanosensor technologies, the development of new direct-reading instruments, Smartphone-connected technologies, and advances in portability, availability, and simplicity of lab and field instruments, will dramatically democratize the collection of data on emissions and environmental concentrations of pollution. Researchers and NGOs are poised to take advantage of these technological advances.

There are numerous examples of the power of monitoring pollution sources. In the U.S., the Bucket Brigades have a history of providing simplified air sample collectors to community groups, which have deployed these collectors at the fence lines of refineries and chemical plants. These kinds of studies will become much easier and cheaper in the near future.

Nearly a decade ago, my team of researchers at NRDC used direct-reading instruments to take simultaneous measurements inside and outside diesel school buses. Our finding (published here) – that the concentration of diesel particulate matter is up to 4 times higher inside the bus than in a car driving ahead of the bus – spurred major action to retrofit and replace old school buses in California and nationwide.

We used the same technology to measure diesel exhaust in communities upwind and downwind of major supermarket distribution centers, resulting in a legal settlement that spurred major clean-up of truck fleets in California.

Just a few years ago, NRDC deployed a direct-reading mercury vapor detection instrument, and discovered higher levels of mercury downwind of cement kilns, compared to upwind. This information helped to spur action at the local level, and also at the U.S. EPA, to regulate mercury emissions from the cement industry.

The new developments in the portability and availability of new monitoring technologies mean that it will be increasingly possible for community groups and smaller NGOs to conduct exposure studies. The instruments can increasingly also be operated by someone without specialized training. At the same time, companies that are developing these technologies are eager for attention. They are therefore willing to lease – or even lend – their instruments to researchers or NGOs for use in short-term studies, with the expectation that publication of the results will encourage broader adoption of their technology. This means that in addition to considering the possibility that government agencies may be monitoring downwind from your facilities, companies can expect that community groups, sometimes in partnership with academic researchers and others, will be monitoring at their fence lines and making the results public via reports or even direct postings to the Internet. Preparing for this not-so-distant future will require companies to take a careful look at their emissions – both to ensure the accuracy of their emissions reporting data, and to take action to reduce emissions, including fugitive emissions, and emissions during start-up, shut-down, and upset conditions.

Because these monitoring devices are so portable, it will not take long for NGOs to deploy them globally, including in developing countries where regulatory oversight is less stringent. High levels of dangerous chemical emissions from facilities in China or India owned by major multinationals may not get much regulatory attention in those countries, but the information could get significant public attention in this country or Europe.

It's time for communities, researchers, and NGOs to think about how they can use the monitoring technologies of the future, because that future may be today.

Advances in Biomonitoring: How New Science Will Change the Game

2011-06-22T14:19:09Z

Gina Solomon, Senior Scientist, San Francisco

Society is on the cusp of major advances in exposure science. These advances will have the effect of generating large amounts of information about what chemicals we are all exposed to (and what gets into our bodies), democratizing the collection and availability of that information, driving improvements in chemical toxicity testing and changing regulatory policy. I'm speaking at a chemical industry conference this week, and am using this as an opportunity to reflect on what’s coming, and to think about what it will mean for NGOs, regulators, and industry – as well as for public health, the environment, and the economy.

In the field of biomonitoring, new analytical instruments - such as the Time-of Flight Mass Spectrophotometer (TOF-MS) and others - allow the screening of biospecimens for tens of thousands of organic compounds. This revolutionizes biomonitoring. Instead of taking a single sample and testing it for a specific chemical, or even for 200 specific chemicals, this approach essentially allows researchers to ask the question: What is in your blood and urine? That’s a very different – and potentially very powerful – approach.

Such strategies are already starting to be deployed in small studies, where researchers today are using the TOF-MS to analyze samples from dozens of pregnant women. When these studies scale-up to involve hundreds or even thousands of people they will become revolutionary, especially since they will be partnered with informatic approaches that allow researchers to answer questions such as:

Which chemicals are most commonly detected in the population?
Which chemicals occur systematically at higher concentrations in sensitive populations, such as young children or pregnant women?
Which chemicals exhibit the largest variability in concentration across populations of interest or across geographic areas?
Which chemicals are increasing over time?
Which chemicals tend to co-occur in certain populations?

All of these questions are important for setting priorities, identifying chemicals of potential concern, and driving research and regulatory agendas.

Historically, we have seen the power of biomonitoring to drive science, public concern, and policy. For example, a decade ago, researchers in Sweden laboriously identified an unknown chemical discovered in their biomonitoring program breast milk samples as pentabromodiphenyl ether. That finding rocketed the PBDE flame retardants into the center of scientific and public attention. There was an immediate demand for toxicity data, for more biomonitoring data, for identification of sources and exposure pathways, and for action, including widespread bans on these chemicals. The PBDEs also created a more generalized public concern about flame retardant chemicals, and sensitized the public to the "whac-a-mole" problem -- where one chemical of concern is phased-out only to be replaced by others that either have their own significant hazards, or are untested.

In another example of the power of biomonitoring, in 2001, researchers from 3M Company published the discovery of PFOA in ‘control’ blood bank samples from the general population. This prompted a business decision by 3M to move away from this chemical in their product lines, and also triggered a decade-long scientific and regulatory effort to scrutinize the toxicity, exposure, and risk from perfluorinated chemicals. Fundamentally, people don’t like to discover potentially hazardous chemicals in their bodies, so biomonitoring has generated dramatic public attention, public concern, and pressure for action. From my perspective, there are still deficiencies in the regulatory response, but at least there is more attention to these problem chemicals, and some regulatory and consumer action has occurred.

My prediction is that the advances in biomonitoring will result in an exponential increase in the discovery of potential chemical hazards in humans. These discoveries will prompt the urgent need for good toxicity testing information, as well as the need for information about the cumulative toxicity of commonly co-occurring mixtures, the uses of these chemicals, and the pathways of exposure. In turn, this information will tend to drive toward more health-protective regulations. The worst position a company could be in is to be blind-sided by the discovery of one if its chemicals in people – especially in vulnerable subgroups such as children – and not have full and adequate data on toxicity, use, and sources of exposure. Industry should take a careful look at their product lines, just to be sure that all of us won't be surprised in the coming years by more nasty discoveries of toxic chemicals in people.

Meanwhile, this is yet another reason why we need a systematic overhaul of our chemical policy law, so that chemicals are tested for toxicity and controlled before they end up in the environment and in people.

Foodborne Illness Rising: The Need for Safer Food and Effective Antibiotics

2011-06-14T20:19:11Z

Gina Solomon, Senior Scientist, San Francisco

Antibiotic misuse in livestock has galvanized young physicians to come help NRDC work on this issue. Michael Turken, a 4th year medical student at UCSF (about to be Dr. Turken!), is working with us to investigate the links between antibiotic use in livestock and foodborne illness in the U.S. Here's his report on a new study from the CDC:

Last week, the Centers for Disease Control and Prevention (CDC) released a new report on foodborne illness for 2010.

In their summary statistics, they state that contaminated food causes an estimated 48 million illnesses, 128,000 hospitalizations, and 3,000 deaths anually. Their data were gathered through the collaborative FoodNet surveillance program, which tracks the most common bacterial culprits: Campylobacter, Listeria, Salmonella, E. coli 0157, Shigella, Vibrio, and Yersinia, in an area of the U.S. that includes 15% of the US population. Unfortunately, five of the "big six" strains of E. coli that are known to sicken people - including the strain responsible for the recent major outbreak in Germany - are not included in the FoodNet surveillance program.

The CDC's results show that while the number of E. coli 0157 infections has declined, Salmonella infections, which have the highest incidence in young children, and are the most common cause of deadly infections, have INCREASED since 2008 and over the last decade. They also found increasing rates of infections caused by Vibrio species. In the attached commentary, the CDC points to the decreasing incidence of E. coli 0157 infections as evidence that it is possible to prevent foodborne infections through better detection and investigation of outbreaks, but that strong action needs to be taken at multiple points, from the farm to the table, by farmers, the food industry, regulatory agencies, consumers and public health authorities.

One of the important corrolaries not mentioned in this report, but explained in great detail by the USDA’s Food Safety Research Information Office, is the strong link between foodborne infections and the growing health crisis posed by increasing antimicrobial resistance (AMR).

Since the early 1970s, when the FDA first suspected that routine use of antibiotics in livestock could stimulate AMR, overhelming evidence from around the globe has, again and again, cemented the link between the dramatic rise in AMR and antibiotic over-use. Currently, 70% of all antibiotics are given to mostly healthy livestock, the same antibiotics that are used to treat serious infections in humans. This alarming trend in AMR is what spurred the NRDC and other concerned organizations to file a suit against the FDA for failing to acts on its own recommendations.

It's distressing to see that rates of several major foodborne illnesses, including salmonella infections, are rising. It's also worrisome to see international outbreaks of other toxic strains of E. coli when we know that the U.S. foodborne illness system isn't even looking for these strains, and there are no strategies in place to deal with them. The FDA must take action to improve food safety, before a major outbreak occurs. One of the key first steps they can take is to ban the misuse of antibiotics in agriculture.

Air Quality and Children's Health: Just the Facts, Please!

2011-06-08T16:46:28Z

Gina Solomon, Senior Scientist, San Francisco

I get nauseated when people use obfuscation cloaked in science to confuse people about issues that relate directly to their health. This morning when I read the testimony of a consultant to industry who is using a Senate committee hearing to attack EPA's regulations on clean air, I felt that familiar nausea.

Julie Goodman, from Gradient Corporation (a consulting firm to numerous polluting industries), uses her testimony to imply that EPA's air regulations aren't based on good science. She couldn't be more wrong.

Julie Goodman's testimony points to a recent report from the National Research Council (NRC) on formaldehyde, which she implies (by association) somehow undercuts the science of all of EPA's regulations. In reality, the NRC report was focused on just one chemical assessment, and the report confirmed EPA's central conclusion that formaldehyde causes cancer in humans. The NRC panel asked EPA to clarify several aspects of its report, and urged the agency to move forward to finalize the report as soon as possible. My colleague Jennifer Sass blogged about the NRC study here. Yes, this recent report on formaldehyde leveled criticisms at EPA for writing a confusing document, but the criticisms weren't really about EPA's science, and it's ridiculous to say that the NRC report somehow eliminates the need to protect children from this cancer-causing chemical - or from other dangerous air pollutants.

The industry arguments at the Senate hearing on Air Quality and Children's health moved from the formaldehyde issue into the realm of fantasy, by implying that somehow the NRC report undermines EPA's ozone standard. Ozone smog is one of the most thoroughly studied pollutants in the world, and the science is overwhelming. The EPA's independent Scientific Advisory Board, the American Lung Association, the American Thoracic Society, and other medical and public health groups have all called for science-based revisions of the EPA ozone standard due to the huge risk to children's health. In fact, the American Academy of Pediatrics has criticized the EPA for not going far enough, based on the science, to protect children's health from ozone smog.

Ozone essentially scorches the airways and lungs, causing cough and pain in healthy people on bad air days. At lower levels, ozone causes asthma exacerbations, increases rates of emergency room visits and hospitalizations for respiratory symptoms in kids, and increases school absences by 63% for each 0.02 part-per-million (ppm) increase in ozone levels. The current regulatory standard is 0.08 ppm, and it's abundantly clear - based on large studies done right here in the United States, that this ozone level sickens kids.

The polluters see the current economic crisis as an opportunity to roll back regulations that cost them money. They have found a few scientists who are willing to stitch together a patchwork of distorted information into a pseudo-scientific fig-leaf for their agenda. But people shouldn't be fooled. The main issue at stake here is the health of our children. If we let the polluters attack the EPA and roll-back clean air regulations, our kids will get sicker, miss school more, end up in the ER, and worse. The nausea that I feel when I read the Senate hearing testimony this morning is nothing compared to the wheezing of children nationwide who will be breathing more polluted air.

The Spread of Antibiotic Resistant Bacteria from Chickens to Farmers

2011-05-31T10:00:00Z

Gina Solomon, Senior Scientist, San Francisco

During the past month, I have been privileged to have a talented young physician, Dr. Julia MacIsaac, working with me at NRDC. Dr. MacIsaac is a specialist in internal medicine who is pursuing subspecialty training at UCSF in occupational and environmental medicine. This month, she has been digging deep into the medical literature about antibiotic use in agriculture and the problem of antibiotic resistance. Here is a blog she wrote about this important topic:

I have been researching the human health implications of feeding antibiotics to healthy livestock – a common practice in U.S. agribusiness. As a physician, this issue is important to me because antibiotic-resistant bacteria make my patients sicker and make the drugs that I rely on less effective. In my research, I came across a particularly compelling study – simple, yet elegant – that captures the essence of the problem.

Dr. Stuart Levy, a physician at Tufts University, tested the bacteria that live in the intestines of farmers and farm communities. As background, it’s important to know that each one of us have millions of bacteria that live in our intestines that are necessary for digestion – they are the healthy bacteria, or so-called bacteria ‘flora’. But, just like bacteria that cause disease, these bacteria can become resistant to antibiotics. Then they can spread the genes that make them resistant to other bacteria that cause disease.

What Dr. Levy and his colleagues did was this: they studied a farm that had not yet incorporated antibiotics into the feed of their chickens – in fact, no feed with antibiotics had been used in the area for at least 7 years prior to the study. They took fecal (stool) samples and studied the bacteria in the stool. They recorded changes over time in intestinal bacteria from the chickens, farm dwellers, and their neighbors. They checked how many of these bacteria were antibiotic resistant, and found that very few were resistant at the beginning of the study.

Then the farm introduced a chicken feed that had an antibiotic in it. It was a tetracycline antibiotic, a drug commonly used in livestock for growth promotion and a drug also used commonly in medicine to treat a variety of common human ailments.

What the group found was this: Within one week of introducing the tetracycline supplemented feed, the chickens’ intestinal bacteria contained almost entirely tetracycline-resistant organisms. The intestinal bacteria of the people who worked on the farm also started to become resistant, but more slowly – it took about 3-5 months to see the changes start to occur. Within 5-6 months however, 31.3% of weekly fecal samples from farm dwellers contained almost entirely (> 80%) tetracycline-resistant bacteria.

The research group also evaluated the effects of removal of the tetracycline-supplemented food from the farm. Astoundingly, within six months after removal of the antibiotic in the feed, no detectable tetracycline-resistant organisms were found (less than 1%) in the vast majority of the farm workers (8 of 10).

This study illustrated how the simple addition of tetracycline antibiotics into chicken feed can breed antibiotic resistant bacteria at first in the chicken, then the farmers, and how the removal of the antibiotic can significantly decrease the number of resistant bacteria.

There is another aspect of this study that is intriguing: After three to four months’ exposure to tetracycline on the farm, the chickens and humans excreted bacteria that were resistant to multiple antibiotics including four OTHER types of antibiotics (streptomycin, ampicillin, carbenicillin and sulfonamides). Resistance to multiple antibiotics was found in more than 50% of the E. coli strains from chickens that ate the tetracycline feed for more than ten weeks. The study found that the genes that provided the resistance for the OTHER antibiotics were linked to the genes that provided resistance to the tetracycline antibiotics. So tetracycline selected for not only tetracycline resistance, but for resistance to other antibiotics.

The authors concluded, and rightfully so, that “The rise in frequency of resistant organisms in our environment is the obvious result of antibiotic usage”, that “The only means to curtail this trend is to control the indiscriminate use of these drugs” and that these data speak “strongly against the unqualified and unlimited use of drug feeds in animal husbandry and speak for re-evaluation of this form of widespread treatment of animals.”

Thirty-five years later, these statements are truer than ever.

You can access the study here (abstract free, full-text requires a subscription): S.B. Levy, G.B. FitzGErald, A. B. Macone. 1976. Changes in intestinal flora of farm personnel after introduction of a tetracycline-supplemented feed on a farm. New England Journal of Medicine. 295 (11): 583-588.

More information on this topic is available on the NRDC website and at Peter Lehner's blog.