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Science Wednesday: The Challenges and Rewards of Health Assessment

2009 August 19

Each week we write about the science behind environmental protection. Previous Science Wednesdays.

Conducting health assessments for chemicals at EPA involves synthesizing the available scientific literature on a particular chemical and determining the health risks that the chemical poses to humans. Personally, I find it fulfilling to be involved in this type of career because the information is useful to the public.

Being a health assessor is rewarding but there are also several challenges in determining how a chemical might act in the human body. One challenge is determining the effect of a chemical in the body when you don’t know much about the toxicological data. There are sophisticated tools, such as microarray analysis and structure-activity analysis, to study compounds with limited information. In microarray analysis, scientists treat particular genes with a chemical and then monitor the results. So if a data-poor chemical has a similar gene profile to an endocrine disrupting chemical, then we hypothesize that this chemical could be a potential endocrine disruptor. Structure-activity analysis helps classify a compound based on its chemical structure. Both of these types of analyses can be completed quite quickly to understand how these data-poor chemicals could act when humans are exposed.

It is also quite challenging when a chemical has been studied extensively. When there is a lot of research on a chemical, arguments sometimes arise about the validity of the research or if a chemical is actually responsible for a resulting health effect. To add to the confusion, although there could be several studies on a chemical, they might not necessarily indicate a clear health effect. In some cases, chemicals have many studies showing health effects in animals but no evident effects in humans.

As health assessors, we generally assume that humans are more sensitive to health effects than animals. Therefore, if a chemical causes toxic effects in animals, then humans should be more susceptible. To reduce this uncertainty, it is important to understand the difference in a chemical’s effect between animals and humans.

Even though there are challenges in evaluating the health risks of chemicals to humans, it is rewarding to know that this information can be used to help keep people healthy. Overall, my job is to understand the potential health risks that could arise from exposures to chemicals in the environment.

About the author: Ambuja Bale works as a risk assessor in EPA’s National Center for Environmental Assessment. She has a PhD in Pharmacology and Toxicology.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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4 Responses leave one →
  1. Johnny R. permalink
    August 19, 2009

    The basic conflict is between long shelf life and health safety. Obviously, the commercial interest is that each product retain an alluring flavor and remain unspoiled on the shelf until sold by any means necessary; whereas the consumer’s interest is to eat whatever tastes good and be happy. This conflict of interest is making millions of people sick as their bodies struggle to process the chemical preservatives and flavor enhancers that lace most of the foods sold today.

    But why is that happening? Because of mass production for millions of customers. If each family could grow its own food on its own land according to organic gardening standards, there would be no need for chemical preservatives and artificial flavoring.

  2. AS Redd permalink
    August 20, 2009

    The research is worthwhile because of cancer and fibroid tumors, though predominantly in African American Women, we are doing something wrong and I believe it has alot to do with food intake! I would like to know more about foods and their link to fibroid tumors! Are chemicals the cause – is it microwaves? What is it? Well research may get to the bottom of all of it.

  3. Michael E. Bailey permalink
    August 22, 2009

    You have a very important job. Chemical companies put chemicals on the market sometimes without doing the testing they need to do to find the impacts on people, We need a check in the form of the USEPA and California EPA to help make sure we are protected. It si supposed that there is chemical involvement in the rate of increase of certain kinds of cancers and in the epidemic rate of certain disabilities like autism. Thank you for the work you do. Best wishes, Michael E. Bailey.

  4. alex permalink
    August 25, 2009

    I found your blog on google and read a few of your other posts. I just added you to my Google News Reader. Keep up the good work. Look forward to reading more from you in the future.

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