Prevalence of Multiple Sclerosis Near Hazardous Waste Sites
In cooperation with state and local public health partners, ATSDR is developing a capacity to respond to community concerns about MS and more fully understand the epidemiology of MS.
Under a grant funded by ATSDR, the Texas Department of Health recently completed an investigation of MS among members of a community living next to a metal smelter. The number of MS cases among this cohort was twofold higher than expected (3). ATSDR has also entered into cooperative agreements with the Ohio Department of Health; the Jackson County, Missouri, Health Department; and the Texas Department of Health. Investigators will use neurologists' records to determine age-specific and sex-specific MS prevalence rates in the study areas of Lorain County, Ohio, Independence and Sugar Creek, Missouri, and a 19-county area around Lubbock, Texas. The three geographically and ethnically diverse study areas include more than 800,000 people. Researchers expect to gather information on 475 to 775 MS cases. The Texas study area also will allow for an estimation of prevalence among Hispanics, a population for which no reliable MS data exist.

Multiple sclerosis (MS) is a chronic disease of the central nervous system. MS is believed to be caused by a combination of environmental, genetic, and immunologic factors. The majority of persons with MS are 40-60 years old and suffer moderate to severe disability (4). MS is approximately twice as common in women than in men, and the number of women reporting MS as a cause of disability has doubled in recent years (4). Estimates of the number of people with MS in the United States have ranged from 125,000 to 350,000 (4, 5, and 6). Residents of several communities living near hazardous waste sites have expressed concerns about perceived elevated rates of MS and the possible association with environmental contaminants. Because no registries for MS exist at the federal, regional, or state level, health agencies have found it difficult to respond to these concerns.

In addition to establishing background MS prevalence estimates for three geographically and ethnically diverse areas, the three grantees will work with local MS support groups and other community groups to help identify individuals with MS and to communicate project findings. In collaboration with ATSDR, grantees will help to develop procedures and data collection instruments to be used for case ascertainment and case verification in other communities concerned about MS. These cooperative agreements will serve as a basis for future studies of MS and an investigation of potential environmental risk factors.

Conclusion
The epidemiology of chronic diseases possibly linked to conditions in the environment must be better understood. Through these collaborative projects, ATSDR will enhance the ability of state and local health departments to work with a variety of data sources and, when feasible, evaluate the contribution of environmental exposures to these conditions.

ATSDR will announce the availability of funding during fiscal year 2003 to support additional activities similar to those described previously. Please check the Federal Register notices for more information, or contact the project coordinators directly at 404-498-0104. These continued efforts are consistent with recommendations made by the Pew Environmental Health Commission in its September 2000 report, America's Environmental Health Gap: Why the Country Needs a Nationwide Health Tracking Network (7). The results of these projects will provide generalizable scientific information and allow the development of a methodology that other state and local health departments could use in responding to questions about the health impact of hazardous substances at specific sites.

References
1. Centers for Disease Control and Prevention. Measuring childhood asthma prevalence before and after the 1997 redesign of the National Health Interview Survey-United States. MMWR 2000;49(40):908-11.

2. US Department of Health and Human Services. Action against asthma: a strategic plan for the Department of Health and Human Services. Washington (DC): US Department of Health and Human Services; 2000. Available from URL: aspe.hhs.gov/sp/asthma/.

3. Agency for Toxic Substances and Disease Registry. El Paso multiple sclerosis cluster investigation, El Paso, El Paso County, Texas [draft for public comment]. Atlanta: US Department of Health and Human Services; 2001.

4. Noonan CW, Kathman SJ, White MC. Prevalence estimates for MS in the United States and evidence of an increasing trend for women. Neurology 2002;58:136-8.

5. Baum HM, Rothschild BB. The incidence and prevalence of reported multiple sclerosis. Ann Neurol 1981;10:420-8.

6. Anderson DW, Ellenberg JH, Leventhal CM, Reingold SC, Rodriguez M, Silberberg DH. Revised estimate of the prevalence of multiple sclerosis in the United States. Ann Neurol 1992;31:333-6.

7. Pew Environmental Health Commission. America's environmental health gap: why the country needs a nationwide health tracking network. Baltimore (MD): Johns Hopkins University; 2000. Available from URL: pewenvirohealth.jhsph.edu/html/home/home.html .