Last week, I posted on the proliferation of unregulated, untested chemicals [1] throughout the environment. The catalyst for that post was the release of the annual report from the President’s Cancer Panel [2], which warned that many of these chemicals were likely to blame for rising cancer rates in the US. The Washington Post wrote: [3]
The current system places the burden on the government to prove that a chemical is unsafe before it can removed from the market. The standards are so high, the government has been unable to ban chemicals such as asbestos, a widely recognized carcinogen that is prohibited in many other countries.
About 80,000 chemicals are in commercial use in the United States, but federal regulators have assessed only about 200 for safety.
The report from the President’s Cancer panel also focused on the potential impact of this chemical burden on children [3]:
Children are particularly vulnerable because they are smaller and are developing faster than adults, the panel found. The report noted unexplained rising rates of some cancers in children, and it referred to recent studies that have found industrial chemicals in umbilical-cord blood, which supplies nutrients to fetuses. “To a disturbing extent, babies are born ‘pre-polluted,’ ” the panel wrote.
Health officials lack critical knowledge about the health impact of chemicals on fetuses and children, the report said.
Now a new study published in Pediatrics [4], the journal of the American Academy of Pediatrics, links pesticide use with the rise in ADHD disorders among children. The study’s authors examined data on over 1,100 children, and determined that elevated levels of pesticide metabolites in the urine was associated with a diagnosis of ADHD. In fact, children with levels higher than the median of the most commonly detected metabolite (known as dimethyl thiophosphate), were twice as likely to be diagnosed as ADHD compared with children that had undetectable levels of the metabolite. The elevated risk factor remained even after controlling for confounding variables like gender, age, race/ethnicity, poverty/income ratio and others.
The pesticides studied belong to a class of compounds known as organophosphates. Time explains [5]:
[Study author Maryse] Bouchard’s analysis is the first to home in on organophosphate pesticides as a potential contributor to ADHD in young children. But the author stresses that her study uncovers only an association, not a direct causal link between pesticide exposure and the developmental condition. There is evidence, however, that the mechanism of the link may be worth studying further: organophosphates are known to cause damage to the nerve connections in the brain — that’s how they kill agricultural pests, after all. The chemical works by disrupting a specific neurotransmitter, acetylcholinesterase, a defect that has been implicated in children diagnosed with ADHD. In animal models, exposure to the pesticides has resulted in hyperactivity and cognitive deficits as well.
Wikipedia explains [6] that organophosphates are a known and potent toxin to humans:
Many organophosphates are potent nerve agents, functioning by inhibiting the action of acetylcholinesterase (AChE) in nerve cells. They are one of the most common causes of poisoning worldwide, and are frequently intentionally used in suicides in agricultural areas. Their toxicity is not limited to the acute phase, however, and chronic effects have long been noted. Neurotransmitters such as acetylcholine (which is affected by organophosphate pesticides) are profoundly important in the brain’s development, and many OPs have neurotoxic effects on developing organisms, even from low levels of exposure.
[7]So why hasn’t the EPA or some similar body regulated these dangerous pesticides out of existence? The key is in part of the Washington Post quotation [3]from above, indicating that “about 80,000 chemicals are in commercial use in the United States, but federal regulators have assessed only about 200 for safety.” Wikipedia elaborates on organophosphates specifically [8]:
The U.S. Food Quality Protection Act (FQPA), passed in 1996, designated the United States Environmental Protection Agency (EPA) to conduct a 10 year review process of the health and environmental effects of all pesticides, beginning with the Organophosphates. The process has taken longer than expected, but was recently concluded and eliminated or modified thousands of uses.
Many non-governmental and research groups, as well as the EPA’s Office of Inspector General, have published concerns that the review did not take into account possible neurotoxic effects on developing fetuses and children, an area of developing research. A group of leading EPA scientists sent a letter to the chief administrator, Stephen Johnson, decrying the lack of developmental neurotoxicity data in the review process. New studies have shown toxicity to developing organisms during certain “critical periods” at doses much lower than those previously suspected to cause harm.
So, a 10-year review that began 14 years ago eliminates thousands of uses, and the government’s own scientists are saying the overdue review still did not go far enough. How confident can we be in the results of the review?
In doing research for this post, I learned some amazing things. For example, a great deal of the research on organophosphates was done by the Nazis [9]. Although the research was initially aimed as using the compounds as insecticides, it turns out that since they are so highly toxic to humans they are ideal candidates for wartime munitions. The lethal fruits of this research include Tabun, Sarin, and VX gases, all of which are now classified as weapons of mass destruction by the U.N. You might remember Sarin gas from the news a few years ago– it was used in the terrorist attack on the Tokyo subway in 1995 [10] which killed 13 people and sickened thousands more.
Another thing I learned when researching this post was that contemporary journalism is in a sorry state. I guess I knew that already, but each fresh instance of poor journalism drives the point home anew. A Reuter’s article I found [11] contained the following paragraph:
Garry Hamlin of Dow AgroSciences, which manufactures an organophosphate known as chlorpyrifos, said he had not had time to read the report closely. But, he added, “the results reported in the paper don’t establish any association specific to our product chlorpyrifos.”
So I guess he scanned this report just to make sure it didn’t name his company’s chemical specifically. When it didn’t call them out by name, I’m sure he breathed a sigh of relief– the shareholders sure wouldn’t like a report like that. Wikipedia’s article on organophosphates [12] notes that a study that did name chlorpyrifos was published in the same journal (Pediatrics) in 2007 [13], which concluded [14] that “children exposed to higher… chlorpyrifos levels were also significantly more likely to experience Psychomotor Development Index and Mental Development Index delays, attention problems, attention-deficit/hyperactivity disorder problems, and pervasive developmental disorder problems at 3 years of age.” I’m still not sure why Reuter’s didn’t find the earlier study significant enough to include in their story, it sure seems relevant to me. I mean, if you’re going to write a story about the link between pesticides and ADHD, then quote a pesticide manufacturer who says “not our chemical!” maybe you should verify that. In any case, Garry Hamlin of Dow AgroSciences should have reminded the reporter of the earlier study, but it must have slipped his mind. It’s too bad that Reuters journalists haven’t figured out to use Google yet, isn’t it?
It turns out that chlorpyrifos was so toxic that it was banned for residential use in 2001 [15], but is still widely used on common crops like corn, wheat, and soy. These crops are also among the most common feedstocks for processed foods. Chlorpyrifos is “one of the most widely used organophosphate insecticides”, according to the EPA [16].
And how is ADHD treated? One of the primary ways is through medication. The National Institutes of Health has this list of medications [17] available to treat ADHD:
| Trade Name | Generic Name | Approved Age |
|---|---|---|
| Adderall | amphetamine | 3 and older |
| Adderall XR | amphetamine (extended release) | 6 and older |
| Concerta | methylphenidate (long acting) | 6 and older |
| Daytrana | methylphenidate patch | 6 and older |
| Desoxyn | methamphetamine hydrochloride | 6 and older |
| Dexedrine | dextroamphetamine | 3 and older |
| Dextrostat | dextroamphetamine | 3 and older |
| Focalin | dexmethylphenidate | 6 and older |
| Focalin XR | dexmethylphenidate (extended release) | 6 and older |
| Metadate ER | methylphenidate (extended release) | 6 and older |
| Metadate CD | methylphenidate (extended release) | 6 and older |
| Methylin | methylphenidate (oral solution and chewable tablets) | 6 and older |
| Ritalin | methylphenidate | 6 and older |
| Ritalin SR | methylphenidate (extended release) | 6 and older |
| Ritalin LA | methylphenidate (long acting) | 6 and older |
| Strattera | atomoxetine | 6 and older |
| Vyvanse | lisdexamfetamine dimesylate | 6 and older |
Quite the list, isn’t it? All of these drugs come with their own side effects to be dealt with. All of these medications have contributed to profits at their respective drug companies, not to mentions insurance companies. The pesticides that we spray on our crops contribute to profits at their respective manufacturers. Dow AgroSciences, the maker of chlorpyrifos, is a wholly owned subsidiary of Dow Chemical Company which reported a profit of $5.7 billion dollars last year [18]. According to Opensecrets.org [19], Dow Chemical had lobbying expenses of $2.375 million dollars last year. We’ve seen the power of Big Pharma’s lobbyists during the recent health care debate [20] as they negotiated a backroom deal with the Obama administration. I can’t help but feel that these corporations are making billions selling us antidotes to the poisons they sold us earlier, while buying off the government agencies that are supposed to be watching out for quaint things like public safety. How else can we explain the utter disregard for any kind of testing (let alone regulation) on the majority of these chemicals for potential harm? Instead, we go ahead and release these chemicals into our environments, breathe them in, eat them with our food, drink them with our water, and then we wonder why cancer [21] and other disorders are so prevalent.
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