Persistent organic pollutant concentrations in first birth mothers across Mexico.

This project was initiated by the North America Commission for Environmental Cooperation (CEC). Its main purpose was to obtain an initial profile on pregnant woman's exposure to persistent organic pollutants (POPs) in North America (Canada, the United States and Mexico). Persistent organic pollutants are transferred to the fetus via the placenta during the pregnancy or to the infant via maternal milk; therefore, the pregnant woman's body burden is important because of the higher exposures and potential health effects in the fetus and infant. This paper presents the results from 240 pregnant women in 10 Mexican cities, and includes the concentrations of various POPs such as polychlorinated biphenyls (PCBs), organochlorine pesticides and polychlorinated dibenzo dioxins and furans (PCDDs and PCDFs) in maternal plasma. We found concentrations of p,p'-DDE in maternal samples from Coatzacoalcos to be ∼60% higher than those found in Ciudad Obregon, which had the second highest concentration. Pregnant women from Merida had higher mean concentrations of PCBs than all women in other regions. Results for PCDDs and PCDFs plus dioxin-like PCBs data were only available on the basis of composite samples, and their concentrations are similar in most cities except for Coatzacoalcos, which had more than double the concentration found in other cities. Although this study provides useful information on the variability of POPs in specific populations and possible regional/local differences, these results cannot be generalized to the entire Mexican population because of differences in age, gender, sources of exposure and nonrandom nature of the sample.

Mercury policy and science in northeastern North America: the Mercury Action Plan of the New England Governors and Eastern Canadian Premiers.

In June 1998 the New England Governors and Eastern Canadian Premiers (NEG-ECP) adopted a comprehensive regional Mercury Action Plan (MAP) with aggressive emission reduction and pollution prevention goals for the New England States, the Atlantic Provinces and Quebec. New Jersey and New York have also been active participants. The NEG-ECP MAP was motivated by, and based on, extensive data demonstrating the widespread and serious nature of mercury impacts in the region and the existence of many preventable sources of mercury pollution. The plan established a long-term goal of virtually eliminating anthropogenic mercury releases in the region with interim goals of a 50% reduction by 2003 and 75% by 2010. Policy and regulatory initiatives implemented under the NEG-ECP MAP have exceeded federal efforts addressing mercury and have resulted in substantial regional progress in reducing mercury pollution. Recent data indicates that the region has reduced mercury emissions by approximately 55% since the NEGECP MAP was adopted. The NEG-ECP MAP provides an important demonstration of what can be technologically, economically and politically accomplished and has influenced mercury reduction programs at the global scale. Scientific information played important roles in developing and implementing this plan. Key research areas where regional policy makers would benefit from additional information include improved: environmental indicators for tracking progress; mercury release inventories, especially on mercury product breakage and mobile sources; deposition sources, including in-region and out-of-region contributors; elemental mercury exposure and impact data; determinants of mercury levels in fish; ecological impacts of mercury; and data on the effectiveness of outreach efforts.

Assessing Canadian inventories to understand the environmental impacts of mercury releases to the Great Lakes region.

North American pollutant release and transfer registries have been continuously developing with an eye to understanding source/receptor relationships and ensuring that the polluter-paid principle is applied to the appropriate parties. The potential contribution of mercury to the Great Lakes Basin arising from the rerelease of historic mercury pollution from contaminated aquatic and terrestrial media is poorly understood and the subject of concern. Although a considerable amount of data may be available on the atmospheric component of mercury releases to the Basin, further inventory work is needed to quantify the rerelease of the historic mercury. Much of the related existing inventory information is either not derived from direct measurement or not bounded by a mass-balance accounting. Critical to this determination is an increased confidence in the inventories of mercury from past and current practices. This may be enhanced through comprehensive and thorough surveys of contributions from specific products and their life-cycle assessments. An even greater challenge is to determine the bioavailability of the mercury emanating from land-based sources and from aquatic media. This paper describes the interplay among the sources and receptors of mercury and provides a quantitative assessment of current Canadian contributions of mercury as a contaminant to the Great Lakes. Recommendations for improved assessments are provided.