One of the ethical challenges facing researchers who conduct biomonitoring studies is how—or whether—to report results to subjects who have provided samples. This is not a particular issue for established contaminants such as lead and mercury because physicians and scientists know how specific levels of these affect health and do not hesitate to inform study subjects. In contrast, little is known about the toxicity or dose-response relationship for many contaminants and health guidelines do not exist. On the one hand, some argue that reporting these results may cause anxiety and stress to the study participants. On the other hand, participants have a right to know all of their results, whether or not there is sufficient evidence about harmful levels.
Two Canadian biomonitoring studies are using different approaches to address this complex issue. As described by Haines and colleagues (2010),1 the Canadian Health Measurements Survey (CHMS) study gives participants the option to access all of their results, while the Maternal-Infant Research on Environmental Chemicals (MIREC) study does not provide this option. Several factors influenced these different approaches, including guidance from the ethics committee for each study, the method of participant recruitment, and the perceived vulnerabilities of each study population.1
Over the past century, evidence has emerged linking chronic, low-level exposure to industrial pollutants or environmental contaminants with many deaths and diseases of industrialized societies, including behavioural problems, asthma, cardiovascular disease, kidney disease, and many cancers.
Physicians are increasingly being asked by patients for advice about treating and preventing an array of diseases and conditions linked with toxic substances. In the future, biomarkers can be expected to help with this by providing more opportunities to investigate and diagnose diseases and conditions related to environmental contaminants.