Observations of childhood 'cancer clusters' in small communities in central California prompted us to examine the distribution of childhood cancer in communities throughout the region to see if the overall cancer rate or the distribution of 'cancer clusters' was unusual for agricultural towns where pesticide exposure might be elevated. The distribution of rates was evaluated using a variety of methods: comparison of rates to the regional average, evaluation of the empirical observed versus expected Poisson distribution of events, and multivariate modelling using Poisson regression. These analyses suggest that there were no previously undiscovered communities with excess rates, although the index community which prompted the initial investigation does stand out as unusual. We discuss the impact of a range of forces of morbidity on the likelihood of 'cancer clusters' and the distribution of observed and expected numbers of cancers in a population of locales.

A follow-up survey of current residents who live near the McColl waste disposal site was conducted to assess community knowledge of an environmental health survey that occurred in the same neighborhood 7 y earlier. Of the 193 eligible adults who participated in an interview (response rate = 73.4%), 35.8% reported having heard of the 1981 health survey; 48% of these (n = 33) reported hearing or seeing the results of the survey. Knowledge of the earlier survey was reported by 34.6%, 40.6%, and 35.7% of respondents in the high-exposure, low-exposure, and comparison areas, respectively. Recall was significantly associated with age (i.e., greater than 55 y), college education, and residence prior to 1981. Our findings suggest that both long-term and recent residents in the study areas know about the McColl waste-disposal site, but the majority of current residents in this sample do not know that the health of the community was assessed in 1981 and that no serious health effects associated with the site were identified. Future efforts to communicate findings of similar health studies should focus on individuals who have less education and on communication with residents who move into an area after a study has been conducted. Creative public participation and media relations should be developed to assure that the results of such studies reach the public.

To assess the effect of interim clean-up measures on the current health of a community, we conducted a follow-up survey of 193 residents living near the McColl waste disposal site and a comparison area located approximately 5 miles from the site. Results from this survey were compared with results from a similar survey conducted 7 years earlier. Odors were detected at least once per week by 32.7% of high-exposed respondents in 1988 compared with 68.5% in 1981, but prevalence odds ratios (PORs) comparing symptom reporting between high-exposed and comparison-area respondents were greater than that of the 1981 survey for 89% of symptoms. PORs comparing symptom reporting between these two areas were greater than 2.0 for 64% of symptoms assessed in the current survey. Symptoms reported in excess did not represent a single organ system or suggest a mechanism of response. PORs comparing respondents who were very worried about the environment and those reporting no worry were greater than 2.0 for 86% of symptoms. These finding, along with environmental data from the area, suggest that living near the waste disposal site and being very worried about the environment, rather than a toxicologic effect of chemical from the site, explain excess symptom reporting found in this follow-up study.

Erythrocytes containing micronuclei serve as an indicator of genotoxic exposure in splenectomized individuals. Micronucleated erythrocytes, derived from cytogenetically damaged RBC precursors, are not selectively removed from peripheral blood in individuals who lack splenic function. The relationship between micronucleated cell frequencies and demographic, environmental, and dietary factors was examined in 44 subjects with previous splenectomy due to trauma. Their micronucleated cell counts fit a log-normal distribution, with geometric means of 3.3 micronucleus-containing cells/1000 reticulocytes and 2.7/1000 normochromatic erythrocytes. A multiple regression analysis showed that drinking five cups of coffee or tea/day (relative to none) was associated with an approximately 2-fold higher frequency of micronucleated cells. Weaker statistical associations were also noted with micronucleus frequency and the consumption of calcium supplements (associated with a higher frequency) and vitamins A, C, or E (lower frequency). An apparent trend of higher micronucleus counts with age was attenuated when other factors were considered in the regression. Cigarette smoking and decaffeinated coffee consumption were among the factors not associated with elevated micronucleated cell frequencies. Because the occurrence of micronuclei in reticulocytes reflects cytotoxic exposures within the past 3-8 days, it may be possible to test directly the relationship of these factors to micronucleus formation through intervention studies.

Aldicarb, a carbamate pesticide, is the most potent pesticide in the market and has a LD50 of 1 mg/kg. In the United States it is illegal to use aldicarb on certain crops, e.g., watermelons, because it is incorporated into the flesh of the fruit. Once an accidental or illegal use of such a potent pesticide occurs, there is no easy way for the agricultural or public health system to protect the populace. This paper describes the impact of one such event upon the health of individuals and the institutions of California. On July 4, 1985, California and other western states experienced the largest known outbreak of food-borne pesticide illness ever to occur in North America. This was attributed to watermelons contaminated through the illegal or accidental use of aldicarb by a few farmers in one part of the state. Within California, a total of 1,376 illnesses resulting from consumption of watermelons was reported to the California Department of Health Services (CDHS). Of the 1,376 illnesses, 77% were classified as being probable or possible carbamate illnesses. Many of the case reports involved multiple illnesses associated with the same melon among unrelated individuals. Seventeen individuals required hospitalization. There were 47 reports of illness involving pregnant women, two of whom reported having subsequent stillbirths. Thirty-five of the remaining pregnant women were followed-up 9 mo after the epidemic; no additional stillbirths were found.(ABSTRACT TRUNCATED AT 250 WORDS)