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NAFTA Overview
The passage of the North American Free Trade Agreement (NAFTA) commits the U.S. to ensuring a safe environment compatible with sustainable development that must accommodate increased industrialization, trade, and population along the U.S./Mexico border. The goals of the EPA's Office of Research and Development (ORD) U.S./Mexico Border project are to:
improve our understanding of the relationship between environmental exposures experienced by residents in the border communities and the potential health risks;
determine the pathways and sources of these exposures; and
use this information, in partnership with the communities, to develop direct educational, training, and pollution prevention/reduction efforts to lower such exposures.
The border communities are predominantly Hispanic populations for which essentially no database on exposure-health risks exists. The border project supports Agency goals for both environmental justice and community-based environmental protection. Moreover, by establishing an Interagency Coordinating Committee (ICC), this project breaks new ground for the Agency. Active involvement has been sought within the EPA as well as several Public Health Service (PHS) agencies, the health and environmental agencies of the four U.S. border states, the Pan American Health Organization (PAHO), and the Mexican agency counterparts. The success of ORD and the ICC is reflected in establishment of environmental health as a formal workgroup of the binational Border XXI Framework Plan.
The population along the U.S./Mexico Border is subject to many known and suspected environmental and health problems. Many of the residents of this area are seasonal or migrant farm workers who have families some with substandard housing; these families may be particularly subject to occupational exposure to agricultural chemicals. The study of this population is of interest to multiple EPA initiatives, besides NAFTA. Because of the location near the U.S./Mexico Border, it is of interest to environmental equity. Since there is a high proportion of low income Hispanics in the population, it is of interest to the children's health initiative because of the potential impact on children of the substandard housing and potential for exposure to environmental contaminants. This study will impact the other studies regarding children's health. This study will evaluate the environmental exposures of the Arizona Border population and test various measurement methods in this predominately Hispanic area which also has extreme climatic conditions.
The NAFTA Arizona Border Study is a probability-based survey of the residents in Arizona in the proximity of the U.S./Mexico Border. The same sampling procedures will be used for selecting participants that were used in the NHEXAS study to assure comparability between the data sets. The NAFTA study includes the collection of questionnaire data and samples for the measurement of contaminants in the air, house dust, water, food, and soil. The blood and urine of the participants were measured for evidence of exposure to environmental contaminants. The program will examine those classes of pollutants that are potentially harmful to human health and for which there is little information on population exposure. There are multiple sources and pathways (for example, air, water, soil, food, and dust) of exposure to these chemicals to the general population. Certain populations, including low-income individuals, minorities and the biologically susceptible, are at high risk and their exposures need to be identified. Further, little is known about temporal and spatial distributions and trends in the distributions of these potentially harmful pollutants. In general, these pollutants are of concern based on limited epidemiological or occupational studies in humans and in animal models utilized for this purpose. Some pollutants are well-known to cause harm and are considered to be of major public health significance; the best examples are benzene and lead. Almost all of these contaminants have documented concerns that are of public health significance relating to their different risks, e.g., carcinogenic or teratogenic. Some health risks and outcomes, like asthma, the clustering of birth defects and some cancers, appear to be increasing.
The NAFTA pollutant classes selected meet the various criteria of a) public health significance; b) potential for study in terms of specific areas where high exposures occur and in which high-risk groups (those biologically susceptible, minorities, low income and/or inner city residents) are easily identified; c) cost and feasibility of determining relevant exposures (and sources) are reasonable and methods are available; and d) feasibility of assessing exposure-dose and dose-response relationships to provide the information directly relevant for risk assessment, management, and for making public health decisions. The pollutant classes selected include (in order of priority) metals, pesticides, volatile organic chemicals (VOCs), and polycyclic aromatic hydrocarbons (PAHs). The list of target compounds were separated into primary and secondary categories.
This NAFTA study also provides an opportunity to evaluate other measurement techniques with little additional effort. The additional techniques being studied are real time PAH monitors which measure airborne PAH on a real-time basis and semipermeable membrane devices (SPMD) which measure airborne pesticides, PAHs, and polychlorinated biphenyls (PCBs).