AngryToxicologist is a scientist in the public health sector, knows plenty about toxicology, and is occasionally angry about it all. Drop me a line at NRC (part of the NAS) released a report saying that EPA's risk assessment is bogged down with all the details they don't know and burdened with assumptions that aren't helpful. Since they were piling on the agency, they threw in the fact that it was silly to look at chemicals in isolation as opposed to a mixture. Well, they were right. As to the issue of always wanting more information, I've wrote about that before, this, I think, is a huge issue for public health today (Science: the enemy of public health).
They are right about the other stuff too. If you're interested, you can go read the report. However, spend some time to shed a tear for the EPA because while the recommendations make sense, some are completely impractical given the statues that give authority to the EPA. For one, how in the heck do you regulate a mixture. Let's say that chemical A, B, and C all contribute to some disease through drinking water. They are all produced by different companies.
Problem 1: Who should have to pay for the research into the mixture? Dividing up this cost is likely to take a long time. Especially since EPA doesn't have very good ways of forcing companies to do toxicology tests on single chemicals.
Problem 2: If each one alone isn't enough to cause the problem, how do you decide how to regulate them. There isn't a way that is obviously fair and therefore, every decision will be fought in court saying that the EPa can regulate it and once that winds it's way through the courts, we'll start another round saying the other company should be the one cleaning it's act more.
Problem 3: How do you test mixtures that exist in different proportions in different communities? You can't do tox tests on every combination that exists and a method that tries to determine what the combinations will do is near impossible (we don't know how to do it for one chemical. How much luck do you think we'll have with a handful?)
I could go on about other practical barriers that the EPA has in implementing these results. But suffice it to say, the EPA can't apply these recommendations under the current laws. But that's not enough; as the NAS notes, the carcinogen TCE has had risk assessment in progress since 1980 and it is projected to be done in 2010. One could rightly ask why bother doing risk assessments at all? It seems that we can either watch the toothless EPA become more and more irrelevant, or Congress can rethink the laws that govern the EPA. And it's not as hard as you would think. Only a few miles away, the FDA does full reviews on drugs to be marketed with greater scrutiny in 9 months or less. There's no reason why the government should make timely and sound decisions about chemicals we take intentionally, but not those that we are involuntarily exposed to.
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Comments
You make an excellent point about the utility (or disutility) of the recent NRC report on improving the risk assessment process. I agree that improving "backend" solutions to protecting the environment and public health from toxics and pollutants--such as the risk assessment process--will have little value, since the statutes by which toxic chemicals are regulated in the United States are so weak. I recently posted a discussion of this topic on CPRblog. http://www.progressivereform.org/CPRblog.cfm?idBlog=19BF84A3-1E0B-E803-CAA3666276979755. I noted there the more basic problem that these statutes have: they do not compel chemical manufacturers to submit to regulators data about the toxicity of the chemicals that they produce. To address this problem, I proposed that the United States amend the Toxic Substances Control Act so that it incorporates something like the European Union's REACH program. The REACH program mandates that manufacturers submit data about the basic toxicity of chemicals they produce as part of a universal chemical registration process; chemicals that are not registered are prohibited from being sold in the marketplace.
It seems clear how the adoption of something akin to the data submission requirements under the REACH program would make the risk assessment process more effective at addressing the risks posed by toxics and pollutants in isolation. Do you think that the adoption of this program's data submission requirements would also help address your concerns about the risks posed by synergistic effects of chemical mixtures? If not, do you have any ideas on how a REACH-style data submission reqiurement could be adapted to address these risks?
Posted by: James Goodwin | December 10, 2008 12:16 PM
James,
Thanks for your thoughful comment and post. There are a lot of good points in there and I'd encourage readers to follow through on that link.
As to REACH, I think it's a bad idea because it's unwieldly and because it's unordinately focused on hazard and not risk. Instead, I'd advocate a system that requires testing information based on results of biomonitoring (probably done by the CDC). Those chemicals that we have proof of being exposed to should get the first and most intensive look. Furthermore, companies should have to develop and make public, methods for human monitoring so that can be done. This roughly what's in the Kid Safe Chemical Act (http://lautenberg.senate.gov/newsroom/record.cfm?id=298072).
Posted by: AngryToxicologist | December 12, 2008 10:02 AM
interesting commentary.
as the number of potentially interacting chemicals increases, so the number of potential interactions goes up exponentially. Do you think that might impact on your idea of testing chemicals if there is an (effectively) infinite number of combinations ?
On testing, you compare with the FDA. The FDA package of regulation costs just under a billion. I can see that you might be able to get away with a phase I animal toxicology package, and get pocket change from, say, $5 million. Do you see any problems associated with that sort of package for all the chemicals we are exposed to ?
yours
per
Posted by: per | December 21, 2008 8:53 PM
Thx.
Posted by: muhabbet | March 18, 2009 10:44 PM
interesting commentary.
as the number of potentially interacting chemicals increases, so the number of potential interactions goes up exponentially. Do you think that might impact on your idea of testing chemicals if there is an (effectively) infinite number of combinations ?
Posted by: islami sohbet | March 24, 2009 1:48 PM
thankss.
Posted by: parça kontör | April 9, 2009 8:03 PM
as the number of potentially interacting chemicals increases, so the number of potential interactions goes up exponentially. Do you think that might impact on your idea of testing chemicals if there is an (effectively) infinite number of combinations ?
Posted by: film izle | May 29, 2009 9:40 AM
as the number of potentially interacting chemicals increases, so the number of potential interactions goes up exponentially. Do you think that might impact on your idea of testing chemicals if there is an (effectively) infinite number of combinations ?
Posted by: islami sohbet | July 4, 2009 6:35 AM
On testing, you compare with the FDA. The FDA package of regulation costs just under a billion. I can see that you might be able to get away with a phase I animal toxicology package, and get pocket change from, say, $5 million. Do you see any problems associated with that sort of package for all the chemicals we are exposed to ?
Posted by: sohbet | July 29, 2009 8:44 AM