{"id":10180,"date":"2021-04-01T10:49:34","date_gmt":"2021-04-01T15:49:34","guid":{"rendered":"http:\/\/blogs.edf.org\/health\/?p=10180"},"modified":"2021-04-01T10:49:49","modified_gmt":"2021-04-01T15:49:49","slug":"re-visioning-tsca-address-the-cumulative-impacts-of-chemical-exposures","status":"publish","type":"post","link":"https:\/\/blogs.edf.org\/health\/2021\/04\/01\/re-visioning-tsca-address-the-cumulative-impacts-of-chemical-exposures\/","title":{"rendered":"Re-visioning TSCA: Address the cumulative impacts of chemical exposures"},"content":{"rendered":"

Richard Denison, Ph.D.<\/a>,\u00a0is a Lead Senior Scientist.<\/em><\/strong><\/p>\n

Part 4 of a 4-part series <\/em>\u2013 <\/em>see Part 1<\/a>, Part 2<\/a>, and Part 3<\/a> here<\/em><\/strong><\/p>\n

This series of blog posts is looking ahead toward opportunities to advance a more robust and holistic vision for implementing the Toxic Substances Control Act (TSCA) as reformed in 2016.<\/p>\n

We discussed in the preceding installments of this series the importance of ensuring that combined exposures to a chemical from multiple sources and the greater exposures and susceptibilities of certain groups are accounted for.\u00a0 But it is critical to also recognize that many other factors influence the impacts chemical exposures have on our health.\u00a0 This final installment in our series will discuss how TSCA can and should take into account all of these factors \u2013 that is, account for cumulative<\/em> impacts.<\/p>\n

<\/p>\n

Recognition of the need to address cumulative impacts has been around for many years but rarely acted on<\/a>.\u00a0 EPA has a framework for cumulative risk assessment<\/a> dating back to 2003, but its use has been limited and it may need to be updated.<\/p>\n

There is every reason for the Biden EPA to start applying cumulative approaches to its chemical assessments under TSCA \u2013 something that EPA\u2019s own Children\u2019s Health Protection Advisory Committee (CHPAC) recently recommended<\/a>.<\/strong><\/em><\/p><\/blockquote>\n

In 2008, the National Research Council of the National Academies published a report titled Phthalates and Cumulative Risk Assessment:\u00a0 The Tasks Ahead<\/a> that provided a roadmap to conducting just such an assessment on just such chemicals.\u00a0 One near-term opportunity to advance a cumulative risk approach under TSCA is to conduct such a risk evaluation for the six chemicals in the phthalates category for which risk evaluations were recently initiated<\/a>.<\/p>\n

While further advances in the science will help strengthen the application of cumulative approaches to chemical assessments, there is every reason for the Biden EPA to start doing so now under TSCA.\u00a0 EPA\u2019s own Children\u2019s Health Protection Advisory Committee (CHPAC) recently recommended<\/a> just that.<\/p>\n

Why is a cumulative impact approach so critical?\u00a0 <\/em><\/p>\n

We know that we are not exposed to one chemical at a time, but rather to complex mixtures of chemicals, whether in our air or water, materials in our homes and workplaces, or products we use.\u00a0 These \u201cco-exposures\u201d can amplify the effects of exposure to a chemical being assessed.\u00a0 Different chemicals can lead to the same or similar health effects, and exposure to one chemical can increase the likelihood of another chemical having an adverse effect.\u00a0 And compromised health status due to prior chemical exposures can make a person more susceptible to the effects of another.<\/p>\n

Scientific studies (see, for example, here<\/a>, here<\/a> and here<\/a>) have also identified non-chemical \u201cstressors\u201d that can exacerbate the effects of chemical exposures.\u00a0 These factors may be individual, socio-economic or environmental.\u00a0 Genetic differences (e.g., variation across the population in genes that affect how well we can metabolize toxic chemicals) can increase an individual\u2019s susceptibility to the effects of a chemical; so too can pre-existing health conditions.\u00a0 Life stage (e.g., in utero or infancy vs. adulthood) impacts susceptibility.\u00a0 We noted in the preceding installment in this series above how social determinants of health such as proximity to sources of pollution, access to health care, and racism<\/a> can alter groups\u2019 risk, by increasing exposure or susceptibility.\u00a0 Exposure to air pollution or excessive heat are examples of environmental stressors.<\/p>\n

Some people are subject to more of these stressors than others, and it is the combined effect of all stressors to which individuals or groups are subject that comprises the cumulative impact<\/em> of chemical exposures.\u00a0 If we are serious about addressing health inequities we must do a better job of considering the cumulative impact of these multiple determinants of health.\u00a0 Moreover, all of these factors are relevant as EPA identifies, evaluates, and mitigates risks to \u201cpotentially exposed or susceptible subpopulations\u201d under TSCA.<\/p>\n

The Trump EPA gave short shrift to such factors in its risk evaluations.\u00a0 It repeatedly failed to explicitly quantify or characterize the increased risk individuals face because of increased susceptibility due to genetic factors or pre-existing health conditions.\u00a0 It also failed even to identify, let alone assess, the heightened risks faced by fence-line and other communities whose residents are disproportionately exposed or experience multiple stressors on top of exposure to the chemical being evaluated.<\/p>\n

An opening under TSCA<\/em><\/p>\n

Looking forward, TSCA presents both challenges and opportunities to robustly address cumulative impacts.\u00a0 One challenge inherent to TSCA is that the entry point into its processes and procedures is through an individual chemical or a category of related chemicals.\u00a0 Prioritization, evaluation and regulatory decision-making are focused on that chemical or category.<\/p>\n

But despite that constraint, there is ample room for EPA to use TSCA to advance the practice of cumulative risk assessment.\u00a0 Such approaches are allowed, and one could argue are in some respects mandated, by TSCA requirements discussed in our previous posts in this series:\u00a0 the requirement that EPA identify, assess and protect against risks to subpopulations subject to greater exposure or greater susceptibility, which demands that EPA consider all factors that could increase exposure to or a chemical\u2019s effect on an individual or group; and TSCA\u2019s requirement that EPA use best available science, which supports if not requires a cumulative risk approach wherever possible.<\/p>\n

 <\/p>\n

Conclusion<\/strong><\/h2>\n

The past four years wreaked considerable damage on TSCA\u2019s implementation and there is a clear need for the Biden EPA to take steps to undo as much of that damage as possible and sharply depart from the legally and scientifically flawed approaches taken by the Trump EPA.\u00a0 But even as it works to right the ship, EPA\u2019s new leadership \u2013 and the nation \u2013 can\u2019t afford to lose the opportunity to advance a more robust and holistic vision for this law, the seeds of which are embedded deeply in some of its core provisions.<\/p>\n","protected":false},"excerpt":{"rendered":"

Richard Denison, Ph.D.,\u00a0is a Lead Senior Scientist. Part 4 of a 4-part series \u2013 see Part 1, Part 2, and Part 3 here This series of blog posts is looking ahead toward opportunities to advance a more robust and holistic vision for implementing the Toxic Substances Control Act (TSCA) as reformed in 2016. We discussed …<\/p>\n","protected":false},"author":100,"featured_media":10179,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[44,5009,114108],"tags":[68,113983],"coauthors":[114100],"class_list":["post-10180","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-policy","category-health-science","category-tsca","tag-epa","tag-re-visioning-tsca"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/posts\/10180","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/users\/100"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/comments?post=10180"}],"version-history":[{"count":1,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/posts\/10180\/revisions"}],"predecessor-version":[{"id":13443,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/posts\/10180\/revisions\/13443"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/media\/10179"}],"wp:attachment":[{"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/media?parent=10180"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/categories?post=10180"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/tags?post=10180"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/coauthors?post=10180"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}