Comprehension and perceptions of study participants upon receiving perfluoroalkyl substance exposure biomarker results.

BACKGROUND:Measurement of environmental biomarkers in biomedia is increasingly used as a method of exposure characterization in human population studies. Reporting the results of biomarker measurements back to study participants has been controversial, including questions of ethics and whether the study participants would want to receive and would understand the results. METHODS:Recently we mailed individual measurements of two serum biomarkers, perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) to participants in three exposure studies of persons living in the Ohio River Valley, of whom 60 were parents of children who had been sampled. Many had serum concentrations of PFOA above the US population 95th percentile value. Reporting forms used in the three studies were somewhat different (either tables or charts for comparison to US population values) and varied in complexity. With all reports, we included information about concentrations of PFOA and PFOS in the general population, and a survey designed to ascertain the opinions of the study participants about the information they received. RESULTS:Approximately 33% (273/821) returned the survey, and of those, 96% reported that they were pleased that we had sent them the report. Most (86%) responded that the results were easy to understand and the enclosed fact sheet was helpful in answering questions (87%). Regarding the amount of information, most felt that we provided the "right amount" (78%) but some "too much" (7%) and some "too little" (15%). The majority (53%) were surprised at their serum concentrations. Of those with serum values > 13.0 ng/mL, 74% responded that they thought their serum concentration was "high", but only 22% of those with serum concentrations ≤5.6 responded that their concentration was "low". Surprisingly, many talked to no one about their levels; those who did were most likely to discuss the report with family members. CONCLUSIONS:Reporting back individual environmental biomarker results is generally well received by study participants, and those with high concentrations perceived them to be high. Questions remain as to why study participants did not discuss their results with others.