Fish Consumption, Mercury Intake, and the Associated Risks to the Kuwaiti Population

ABSTRACT

This analysis uses recent data on fish consumption among Kuwaitis and on levels of Hg in fish collected from fish markets in Kuwait to estimate the human health risks to the Kuwaiti population due to consumption of fish containing Hg. Mercury is a known human neurotoxicant. Recent, somewhat controversial, evidence suggests that it also may play a role in cardiovascular disease. Our analysis indicates that roughly 5,000 IQ points are lost among the 30,000 Kuwaiti infants born each year and that approximately 15 fatal heart attacks each year among middle-aged and elderly Kuwaitis may be attributed to consumption of methyl Hg in fish. Approximate 90% confidence intervals are from 1,800 to 14,000 IQ points lost annually and from 0 to 72 fatal heart attacks each year. The confidence intervals for neurotoxicity are broad because of uncertainty about the slope of the dose–response and the existence of a threshold. The range of estimates for heart attacks includes zero because of residual uncertainty about the causality of observed associations between methyl Hg exposure and cardiovascular disease. These results do not imply that Kuwaitis should immediately reduce their consumption of fish, but do suggest that a careful risk–risk tradeoff analysis may be warranted.

Key Words:

• methyl Hg
• Kuwait
• fish consumption
• neurotoxicity
• cardiovascular disease.

ACKNOWLEDGMENTS

This analysis was supported by a grant from the Kuwait Environmental Public Authority to the Kuwait Institute for Scientific Research (KISR), and by a subcontract from KISR to JS Evans and Associates. The fish consumption data were collected as part of the Kuwait Public Health Survey II (PHS II) funded by Kuwait's Public Authority for Accounting for Compensation (PAAC). Drs. Evans and Akashah also received support from the Kuwait Foundation for the Advancement of Science. We sincerely thank all of these sponsors for their support of our work.

Notes

This is an approximate relationship. The exact expression, used in the Analytica model, for heart attacks attributable to Hg exposure is {[(exp(−ρ _c,h *M_i ) − 1)/(exp(−ρ _c,h *M_i )] * H_i } where M_i is the hair Hg concentration in the ith sex category computed from their fish consumption, F_ijk , the Hg concentration in that fish, C, and the coefficients relating intake to blood Hg, β _i,b , and blood Hg to hair Hg, β _b,h .