Establishment of an exposure level to tetrachloroethylene in ambient air in Vermont.

Where environmental contaminants pose potential health hazards, health departments are involved in complex and often controversial situations. Often the rapid formation of a threshold exposure level is required to protect public health. A decision making process was implemented in Vermont when it became necessary to have an interim ambient air exposure level to test for tetrachloroethylene contamination in the water, air, and soil of a community. Contamination of public and private drinking water and ambient air in schools and homes was discovered as a result of uncontrolled waste disposal from an industrial uniform laundry and drycleaning plant. A telephone survey was conducted to determine action taken by the other 49 States regarding emission standards for tetrachloroethylene into ambient air. There were no guidelines in 25 States, and there were guidelines in the remaining 25. Vermont's Commissioner of Health convened a multidisciplinary group of public health professionals to review various approaches to the establishment of an ambient air standard. A decision making action using modified Delphi and nominal group consensus methods set the interim standard at 67 micrograms per cubic meter in ambient air. The drycleaning plant had been closed voluntarily before the standard was established, and the interim standard was used to prevent reopening of the plant through a health order issued by the Vermont Health Department. The standard was also useful for guidance during environmental remediation.

Legionella in cooling towers.

Legionellosis (Legionnaires' disease and Pontiac fever) outbreaks have been associated with aerosols ejected from contaminated cooling towers--wet-type heat rejection units (WTHRUs) used to dissipate unwanted heat into the atmosphere. The Vermont Department of Health undertook a program to inventory, inspect, and sample all WTHRUs in Vermont from April 1981 to April 1982. All WTHRUs were sampled for Legionella pneumophila and data were obtained for location, design, construction, and operating characteristics. Of the 184 WTHRUs operating, statistical analyses were performed on those 130 which were sampled for L. pneumophila only once during the study period. Of these, 11 (8.5%) were positive for L. pneumophila. Sources of makeup water and period of operation had significant association with the recovery of L. pneumophila. Five out of 92 towers (5.4%) utilizing surface water sources for cooling were positive for L. pneumophila, in contrast to 6 positive towers of the 38 units (15.8%) which obtained makeup water from ground water sources (p = .054 by chi-square test). Nearly 15% of the 54 units which operated throughout the year were positive, compared to less than 4% of the 76 towers operating seasonally (p = .03 by chi-square test). The mean pH of the cooling water in units where L. pneumophila was recovered (8.3) was significantly higher than the mean pH of 7.9 in units testing negative (p less than .05 by t-test). In addition, the mean log-transformed turbidity of positive towers, 0.03 nephelometric units (ntu), was significantly lower than the mean of log turbidity of negative towers, 0.69 ntu (p less than .02 by t-test).

Tuberculosis in employees at a Vermont furniture plant.

In a case-contact investigation of a patient (A) with smear- and culture-positive pulmonary tuberculosis, we found that co-workers in one room of a furniture factory had a higher prevalence of significant reactions to 5 Tu PPD tuberculin than other furniture factory workers. One co-worker also had active pulmonary tuberculosis. It was concluded that Patient A probably transmitted mycobacteria in a well-ventilated, spacious work setting; and that Patient A's disease and the subsequent outbreak could have been prevented.

Pontiac fever associated with a whirlpool spa.

In March 1981, an outbreak of 34 cases of Pontiac fever occurred among 74 members of a social club who visited an inn in south-central Vermont. Environmental and epidemiologic investigations were done to identify the causes of the illness. The outbreak of Pontiac fever was most likely caused by L. pneumophila, serogroup 6, which was identified in a whirlpool spa at the inn. This is the first reported instance of an outbreak of Pontiac fever associated with a whirlpool spa.

National survey on outbreaks associated with whirlpool spas.

A national survey of state epidemiologists sought information on reported outbreaks of illness associated with non-residential whirlpool spas for the period April 1972-July 1, 1982. Reports were received from 49 states. Of the 74 whirlpool-associated outbreaks reported, 72 were characterized as having patients with papular or pustular rash and two were associated with cases of Pontiac fever.

Legionnaires' disease: the epidemiology of two outbreaks in Burlington, Vermont, 1980.

Eighty-five cases of Legionnaires' disease were diagnosed in two major outbreaks at a large regional medical center in Burlington, Vermont, in the summer of 1980. Cases in both outbreaks were positive for Legionella pneumophila, serogroup 1 by culture, serology, or direct fluorescent antibody tests. All cases had spent time in the city of Burlington in the 10 days before the onset of symptoms. Cases in both outbreaks were both hospital- and community-acquired. A case-control study identified no common in-hospital exposure, including shower use, that was associated with illness. Cases without previous exposure to the hospital were more likely to occur in persons with residences in neighborhoods just downwind of cooling tower A, but not throughout the municipal water system. Epidemiologic and environmental studies supported the association of this cooling tower, located 150 m from the hospital, with both outbreaks. Maintenance employees who worked with tower A had higher Legionella titers than those who worked with a comparison tower located 1.6 km away. Aerosolization of L. pneumophila by tower A and airborne spread to the hospital and community are postulated. The distance of airborne transmission of L. pneumophila in these consecutive outbreaks is greater than previously reported.

Increased lead absorption in children of workers in a lead storage battery plant.

Exposure to toxic materials originating in the workplace has been recognized in families of workers in several industries. However, to date this problem has not been studied in the storage battery production industry. Twenty-seven one- to six-year-old children of 22 workers at a storage battery plant at high risk of exposure to lead oxide were compared with 32 one- to six-year-old children in 22 neighborhood control families for evidence of increased lead absorption. Workers' children had significantly higher blood lead (p less than 0.001) and erythrocyte protoporphyrin (p less than 0.003) values than control children. Household exposures to lead in paint and water were similar for the two groups, but workers' homes had significantly higher concentrations of lead in dust (p less than 0.001). It is postulated that lead is brought home on the skin, hair and clothing of the workers and that their children are ingesting or inhaling the lead in household dust. This is the first report of increased lead absorption in children of workers in this industry.