This Issue

This issue of Hazardous Substances and Public Health examines the relationship between diseases and the environment. Environmental factors can cause illness or make it worse. Therefore, it is important to examine and understand the links between the environment and human health so that we can lower our risk for illness or disease. In this issue, we look at asthma, multiple sclerosis, endocrine disruptors, chronic beryllium disease, and
disease clusters, all of which have been linked to the environment.

Following is an overview of some of the articles.

Asthma and Multiple Sclerosis: Developing Epidemiologic Tools To Investigate Disease in Communities Impacted by Toxic Substances addresses cooperative agreements between the Agency for Toxic Substances and Disease Registry (ATSDR) and several states. A companion article discusses ATSDR’s cooperative agreement program.

Environmental Triggers of Asthma examines potential asthma triggers and how to control or avoid exposure to those triggers. Two other articles discuss resources on asthma and the new ATSDR Case Studies in Environmental Medicine: Environmental Triggers of Asthma, which offers continuing education credit.

Endocrine Disruption: Is There Cause for Concern? discusses the hypothesis of environmentally mediated disruption of the endocrine system. Endocrine disruptors are environmental chemicals that may have an adverse effect on human and ecologic health by disrupting normal hormonal systems. The article includes background information on endocrine disruption and recommendations of the National Research Council’s Committee on Hormonally Active Agents in the Environment. A company article discusses the controversy over appropriate terminology for endocrine disruption.

Beryllium Exposure and Chronic Beryllium Disease discusses the health effects of exposure to compounds of beryllium. A companion article examines the Elmore, Ohio, Brush Wellman Company plant site, the primary U.S. producer of beryllium powder. In October 2001, ATSDR issued a health consultation for the site, and in fall 2002 the agency will complete an exposure investigation.

New Director, ATSDR Division of Health Studies

Dr. G. David Williamson, a Department of Health and Human Services Distinguished Fellow, joined the Agency for Toxic Substances and Disease Registry (ATSDR) in summer 2001 after 14 years in the Epidemiology Program Office (EPO), Centers for Disease Control and Prevention (CDC). He is Adjunct Professor, Departments of Biostatistics and Epidemiology, Rollins School of Public Health, Emory University, and serves as Executive Director, CDC/ATSDR's Statistical Advisory Group (SAG). In the SAG role, he provides leadership for the development and coordination of statistical and analytic methods activities, including statistical consultation, communication, recruitment and retention, seminars and training courses, and symposia across both CDC and ATSDR.

Dr. Williamson is a member of the CDC/ATSDR Excellence in Science Committee as liaison to represent the statistical/analytic methods communities for the agencies. He is also a member of the U.S. Office of Management and Budget's Federal Committee on Statistical Methodology, the group that addresses and makes recommendations to the federal government on methodologic and statistical issues that affect the quality of federal data.

Dr. Williamson was born in Savannah, Georgia, and received his undergraduate degree in biology from the Georgia Institute of Technology. He received a master's degree in biology (with a focus in estuarine ecology) from Georgia Southern University, for which much of his work was performed at the Skidaway Institute of Oceanography. He received a master's degree in statistics from Virginia Polytechnic Institute and State University and his doctoral degree in biostatistics from Emory University. Before joining CDC, Dr. Williamson worked at the U.S. Environmental Protection Agency and at the Louisiana State University Medical Center.

Dr. Williamson is an active member of a number of professional societies, including the American Public Health Association, the American Statistical Association (ASA), and the International Biometrics Society. He was Program Chair for the 2000 Joint Statistical Meetings, with responsibility for assisting in determining the scientific agenda for the ASA and developing the agenda for the largest annual meeting of statisticians in the world. He has recently been named Vice Chair, Committee on Meetings, ASA, with responsibility for guiding ASA participation in all the association's sponsored meetings and conferences.

Childhood Asthma and Hazardous Substances

In 1999, ATSDR entered a 3-year cooperative agreement with the Utah Department of Health and the Massachusetts Department of Public Health to conduct asthma research. Studies conducted under this cooperative agreement will examine patterns of asthma among children in relation to estimates of exposure to hazardous substances. The purposes of this program are threefold:

• to use available data sources on asthma to evaluate the contribution of environmental exposures to asthma among children,
  
  
• to provide generalizable scientific information about the association between hazardous substances and childhood asthma, and
  
  
• to develop a methodology that could be useful in responding to questions about the health impact of air releases of hazardous substances.
  

Analysis of Childhood Asthma and Hazardous Sites in Utah
Under this project, the Utah Department of Health will study variations in the risk for childhood asthma in four urban counties and determine whether rates of asthma increase in children living near hazardous waste sites or industrial emission sources. Data from almost 20 hospitals in four urban counties will be used to obtain data on asthma for children zero to 14 years of age. This project will use geographic information systems (GIS) to identify high-risk areas, which can lead to public health action. Analyses will identify areas with high incidences of childhood asthma and assess the cases of asthma alone and in relation to sources of potential hazardous substances.

Pediatric Asthma in the Merrimack Valley, Massachusetts
In a two-part study, the Massachusetts Department of Public Health aims to

• assess whether the pediatric asthma rate in each community in the Merrimack Valley is higher than the rate from a demographically similar comparison community and
  
  
• compare pediatric asthma rates in areas in the valley where the possibility is higher for exposure to incinerator emissions to areas where the possibility for exposure is lower.

The project will use school health records to identify students with asthma and will collect environmental data from the Massachusetts Department of Environmental Protection. GIS will be used to map the locations of the pediatric asthma cases and sources of exposure.

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.

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 .

The Agency for Toxic Substances and Disease Registry (ATSDR) works with state health departments, state environmental agencies, local health departments, and the U.S. Environmental Protection Agency (EPA) to determine the possible public health effects of exposure to hazardous substances from sites on EPA's National Priorities List for Uncontrolled Hazardous Substances (NPL; known as Superfund sites). From its beginning in the 1980s, ATSDR sponsored cooperative agreements with states. Over the years, the work completed by ATSDR's state cooperative agreement partners has gone beyond sites on the NPL to include other sites of concern to local communities.

Recently, ATSDR completed two successful state cooperative agreement programs, known as Program Announcement (PA) 607 and PA98064. ATSDR is beginning a new cooperative agreement program, known as PA1043, which merges PA607 and PA98064 into a new unified program. Formally known as the "Program To Conduct and Coordinate Site-Specific Activities," PA1043 funds 31 state health departments, one commonwealth health department (Puerto Rico), and one tribal group (Gila River Indian Community). The 33 recipients were awarded a total of more than $11.1 million, says Sharon Conley, one of ATSDR's project officers for the cooperative agreement program. The positions funded under the cooperative agreement program include environmental health scientists, health educators, health assessors, epidemiologists, and others, depending on the needs of the partners.

How the Program Works

To coordinate activities between ATSDR and the PA1043 recipients, Technical Project Team (TPT) members participate in monthly conference calls. TPTs include three ATSDR technical project officers, a regional office representative, and state-level staff. At the beginning of the fiscal year, TPTs agree on a workplan to guide site-specific activities for the year. The workplan is a fluid document and is modified by TPTs as new sites are added and priorities change.

Once a site is listed on a workplan, a variety of activities occur. Working together, the team might conduct one or more public health assessments or health consultations. Simultaneously, the health educator conducts a needs assessment of community members and health professionals. Health education for community members and health professionals will be developed on the basis of the needs assessment. Finally, a variety of follow-up activities, including an exposure investigation, might be initiated if warranted.

As with site work performed by ATSDR headquarters staff, stakeholder involvement is critical to the success of activities funded by the partners cooperative agreement program.

Measuring Success With STARS

An important improvement in the new cooperative agreement program is ATSDR interdivisional coordination, which played a role in the current pilot testing of a new reporting system known as STARS (Site Tracking and Reporting System). "Historically, we had multiple reporting documents," says Grant Baldwin, one of the technical project officers administering the cooperative agreement program. Each ATSDR division had its own programmatic reporting software the partners were required to use. Now, he states, "STARS mirrors the level of integration we'd like the partners to do." Previous state cooperative agreement program recipients requested this interdivisional coordination.

According to Linda Stacy, chair of the STARS Team, STARS is being tested by 20 states. Testing began with 12 states, but the project officers "were so pleased with the database that they've been bringing more states on board during the pilot testing," Stacy says. All 33 funding recipients should be in the system by the second quarter of FY 2002. Developed in Microsoft Access, STARS data can be uploaded into ATSDR's Hazardous Substance Release/Health Effects Database (HazDat). The new reporting system will replace the partner workplans that were entered into HazDat from a word-processing report. These workplans had incomplete data and data entry was time-consuming. STARS improves and streamlines the reporting mechanism and provides a better mechanism for reporting the public health benefit of activities and programs.

"We're excited about STARS because it not only tracks but also identifies the customer and evaluates the benefit of the activities," Stacy says. The STARS team has developed objectives that are linked to ATSDR's goals, which enables the agency to fulfill the mandates of GPRA (Government Performance and Results Act), she says. Another unifying feature is that STARS reports activities not as division activities but as agency activities.

The partners cooperative agreement program is a benchmark program for ATSDR. PA1043 and STARS will continue to build on this success.

To achieve successful asthma control and effective long-term management, it is important to identify allergens, irritants, and pollutants that trigger asthma so asthma flare-ups can be prevented. Making changes in individual and family behavior and complying with treatment regimens also play important roles in the successful control of asthma. Resources on asthma can be found in the sidebar article.

Allergens

Allergens are substances capable of inducing an allergy or a specific hypersensitivity reaction. The most important step in controlling allergen-induced asthma is reducing exposure to the agents to which the patient might be sensitive. Reducing exposure will help prevent exacerbations of asthma.

For children, allergens might be encountered at home, in their classroom or day care center, on the playground, during family moves or house renovations, and during weather changes and seasonal variations.

Adults are affected by the same allergens that affect children. Adults can also be exposed to allergens in the workplace.

Cockroach Allergen: This allergen is more of a problem for people with asthma who live in low-income housing. The severity of asthma in these patients is directly proportional to the levels of cockroach allergen in their bedrooms.

Animal Allergens: All warm-blooded pets, including birds and small rodents, can cause allergic reactions in sensitive patients because of dander and body secretions (urine, feces, and saliva). Dander is small scales from the hair, skin, or feathers of animals.

House Dust Mites Allergen: The survival of mites depends on increased relative humidity and on human dander. Increased concentrations of mites are in all bedclothes (dust covers, pillows, and mattresses), upholstered furniture, carpets, clothes, and stuffed toys.

Pollens: Pollen from trees, grass, or weeds can be a problem, especially during spring and fall seasons.

Indoor Mold: Indoor mold can be found where humidity levels are high, such as in bathrooms (especially bathrooms without windows and bathrooms with leaking faucets) or basements, and in homes where dampness is a problem. Inspecting rooms for molds, such as looking under old carpets, might reveal areas covered with mold.

Irritants

Fumes From Wood or Gas Stoves: Malfunctioning stoves (gas, oil, kerosene, or wood), fireplaces, or strong odors can irritate the lungs, precipitating asthma symptoms.

Environmental Tobacco Smoke (ETS): ETS is a major precipitant of asthma symptoms and the most important and preventable indoor environmental irritant. ETS exposure is associated with early onset of asthma symptoms, increases in asthma exacerbations, consequent increased use of medication, and lengthened recovery periods. Prenatal exposure to ETS can adversely impact a child. Maternal smoking during pregnancy (as few as 10 cigarettes per day) has been associated with an increased risk of the child developing asthma later in life.

To help control exposure to cockroach allergen Discard food leftovers: exposed food or garbage residue can attract cockroaches. Limit eating areas to dining room and/or kitchen. Use traps instead of chemical agents for pest control. When chemical agents are applied, make sure that sensitive patients are kept out of the area. Ventilate the premises for several hours or until the chemical odor is gone. To help control exposure to animal allergens Remove the pet from the house (preferred). If removal is not feasible, keep the pet out of the patient’s bedroom and keep the door closed. Remove carpets and upholstered furniture from the patient’s bedroom or family home or isolate the pet from these items. Wash the pet and change litter frequently (once a week) to decrease the amount of dander and/or body secretions from its hair or feathers. To help control exposure to, and levels of, house dust mites Use allergen-impermeable mattress and pillow covers, and damp-wipe them clean once a week. Wash stuffed toys and bedclothes in hot water (temperature of 130°F [54°C]) to kill the mites. Use a damp wipe to clean the patient’s bedroom furniture. Use a high-efficiency particulate air (HEPA) filter vacuum cleaner. To help control pollen allergy Stay indoors with the windows closed during peak pollen seasons. Clean air filters frequently. Use antiallergic medical control. To help control indoor mold Avoid using humidifiers. Maintain indoor humidity at <50%. Fix leaking faucets and eliminate standing water. Do not allow sensitive patients in problem areas such as the basement. To help control exposure to fumes from wood or gas stoves Ensure proper functioning of stoves and fireplaces. Use kitchen vents when cooking. To help control exposure to environmental tobacco smoke Parents who smoke should quit; if they are unable to quit, they should smoke outside—never in the home or in the family car. If children attend day care, ensure that day care staff do not smoke indoors.

Outdoor Pollutants

Nitrogen Dioxide (NO₂): In contrast to the other pollutants in this section, NO₂ is both an indoor and outdoor air pollutant. Sources of indoor NO₂ include malfunctioning gas stoves, furnaces, fireplaces, and kerosene space heaters. The effects of NO₂ are thought to be due to long-term, low-level exposure. NO₂ exposure that occurs when the patient is exercising or running might be more irritating to airways than exposure that occurs when the patient is not exercising.

Particulate matter (PM₁₀ and PM_2.5): Particulate matter is a mixture of solid particles and liquid droplets. The sources and potential health effects of particulate matter are different for the two sizes.

• PM₁₀, particulate matter 10 micrometers (µm) in aerodynamic diameter, is associated with exacerbation of existing asthma. Sources of PM₁₀ include dust and street sand from crushing or grinding (i.e., construction work), vehicle exhaust, and smoke from burning wood.
  
  
• PM_2.5, particulate matter 2.5 µm in aerodynamic diameter, penetrates deeper into the lung, thus producing greater health effects. PM_2.5 can precipitate asthma symptoms. Sources of PM_2.5 include industrial and residential combustion, vehicle exhaust, and atmospheric reactions between gases (SO₂ and NO₂) and volatile organic compounds (VOCs).

Ozone (O₃): O₃ is the most potent irritant of the outdoor air pollutants. Its effect is immediate. O₃ is suspected to induce or enhance the inflammatory response of the respiratory system. In the United States, a large fraction of ambient O₃ is the product of photochemical reactions between various nitrogen oxides (NO_x) and VOCs emitted from vehicles.

Sulfur Dioxide (SO₂): SO₂ is highly soluble. The nasal mucosa can fail to remove SO₂, leading to upper airway irritation and subsequent penetration into the lung tissue. Greater exposure to SO₂ might occur in persons who have asthma and who exercise. SO₂ levels have been decreasing over the last 15 years, so it is unlikely that SO₂ alone is responsible for the recent increases in the prevalence of asthma.

Outdoor mold: Outdoor mold can be found in shady, damp areas or places where leaves or other vegetation are decomposing. In warmer states, mold spores begin to show early in spring; levels of spores peak in July. In colder states, the peak for mold spores occurs during the fall. Children playing outside or adults raking leaves might be exposed to those spores. Molds can be found year-round outdoors in the South and on the West Coast.

Conclusion

Various environmental factors can trigger exacerbations of asthma. Interventions are available to mitigate these factors. Identifying possible asthma triggers and taking preventive action to reduce those triggers are imperative to achieving successful asthma control and effective long-term
management.

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This page last updated on October 24, 2003
Contact Name: Wilma López/ WLópez@cdc.gov