Do you want to know your ‘body burden’?

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Publication Date: 
Mon, 2014-03-03

Recent clinical studies indicate that BFRs may impact early stages of human development and at least one outcome is abnormalities of the reproductive system. Levels of BFRs in the environment and in humans in North America are on the rise. The body burden of BFRs in North Americans has risen sharply since the early 1990s to reach a level among the highest in the world. Most of the consumer products containing BFRs are found in homes and offices, since the substances are used to reduce flammability of carpet fibers, foam, mattresses, wiring, computers and other electronics. We spend over 80 per cent of our time indoors and the indoor environment has 1.5 to 50 times greater levels of BFRs compared to the outdoor environment.

A wide variety of consumer products contain phthalates. These include products made of flexible polyvinyl chloride plastic (PVC), cosmetics and other personal care goods, pesticides, building materials, lubricants, adhesives, and film, among other items. Phthalates are released into the environment during manufacturing processes and leach from consumer products. Human exposures are commonplace as a result of worldwide ecosystem contamination and direct contact with products containing phthalates.

Reporting results

Communicating study results is one of the greatest ethical challenges facing researchers who conduct biomonitoring studies. It is unclear what type of information to relay to study participants, but it is also unclear how it should be done. In many cases, study participants are now demanding to see their individual results, despite the lack of knowledge about individual health effects due to exposures.

Reporting study results to individuals is particularly difficult because participants usually want to know if they are healthy. Biomonitoring studies are not designed to answer that question. Biomonitoring accurately measures exposures, but the data do not indicate a particular state of health, nor do they indicate an individual’s likelihood to develop an illness. Also, for many of the chemicals measured in contemporary exposure studies there is no readily available range of acceptable levels of concentrations in human blood, urine, or other biological specimens.

Researchers have a duty to limit risk and must consider the potential harm of reporting results. Individuals may experience fear, worry, or stigma; there are legal and economic complications, such as effects on health insurance or property values related to chemical contamination; and the possibility of unnecessary or counter-productive interventions. Because responsible reporting is expensive (financial costs include creating a customized report for each individual and often a face-to-face meeting), it may cause unintended harm, not to mention the use of resources that would otherwise be spent on health or services (Read “Improving Disclosure and Consent").

Currently, scientists or community-based research collaborations receive minimal guidance on the matter of reporting results. According to the clinical ethics model, researchers should only communicate individual results if exposure levels are deemed significantly high or if the exposure level is clearly linked to a harmful outcome, such as in the case of lead. In some studies only physicians are permitted to share the results and are meant to adequately explain risk levels associated with the chemicals in question.

If a participant’s biomonitoring results are below the regulatory levels, even if evidence suggests health concerns at lower levels, the clinical model does not allow for precautionary action. For the majority of chemicals tested in biomonitoring studies no adverse health outcomes are conclusively linked to low-level exposures. However, not reporting individual results may become a problem as new research continues to link exposures and health outcomes in the future. Even in the absence of regulatory benchmarks, individuals could compare their results with average exposure levels in the general population.

Reporting individual results may have negative consequences. For example, recent studies on the presence of PBDEs, PCBs and other toxins in breast milk have raised concerns that if women have knowledge of high levels of toxins, they will stop breastfeeding. However, research shows that appropriate biomonitoring study design, including clear communication about individual results and the benefits of breastfeeding, can prevent these negative impacts on breastfeeding.

The clinical model policies also make researchers into gatekeepers of participants’ information instead of offering participants the opportunity to decide for themselves what research information they want to know. Failing to report biomonitoring results to participants treats individuals as sources of scientific data without considering their interest in receiving information about themselves. Research shows that the prevalence of distress caused to participants by disclosure is low and that most participants find disclosure of test results beneficial, regardless of the actual result or accompanying distress.

An alternative to the clinical model is community-based participatory research (CBPR), which assumes that reporting individual and aggregate study results can empower individuals and communities to act on scientific research. CBPR encourages as much dissemination of information as possible and asserts that the collected data belong primarily to the study participants.