Mercury is a global contaminant with toxic, persistent effects on human health. Petroleum extraction is an important source of elemental mercury; little is known about human exposure levels near oil fields in the Amazon basin.Objectives
To characterize mercury levels in people living near oil production sites in the Peruvian and Ecuadorian Amazon, controlling for fish consumption, occupation, source of water and socio-demographic characteristics.Methods
Analyze mercury levels in urine samples using cold vapour atomic fluorescence spectrometry from 76 indigenous men and women in eight riverine communities situated near oil wells or pipelines. Subjects answered a questionnaire soliciting socio-demographic, occupational and dietary information. Data were analyzed using multiple linear regression modeling.Results
The mean value of U-Hg was 2.61 μg/g creatinine (95% CI: 2.14–3.08), with 7% of the sample recording values above the global background standard suggested by The World Health Organization (5 μg/g creatinine). Women who used water from a surface source had two and a half times the amount of mercury in their urine (mean=3.70 μg/g creatinine, 95% CI: 2.26–5.15) compared with women who used other water sources (mean =1.39 μg/g creatinine, 95% CI: 0.51–2.25). Men who were involved in an oil clean-up operation had twice as much mercury in their urine (mean =3.07 μg/g creatinine, 95% CI: 1.97–4.16) as did those who worked on other tasks (mean =1.56 μg/g creatinine, 95% CI: 1.48–2.65). Mercury levels were not associated with the number of fish meals per week.Conclusions
Indigenous peoples of the Peruvian and Ecuadorian Amazon living near oil production sites generally had urine mercury levels within the global background standard suggested by the World Health Organization. Increased levels of mercury in urine were detected for men involved in oil spill remediation and for women who relied on surface water for household needs. These findings signal the need for strict safety measures to limit the amount of oil entering the waterways in Andean Amazonia so as to protect the health of indigenous people.