Enteric illness risks before and after water treatment improvements.

This study evaluated whether occurrence of acute gastrointestinal illnesses declined after filtration and ozonation were added to a previously unfiltered, chlorinated high-quality surface water source in a northwest United States city. Enteric and other illnesses were recorded for two 6-month periods for control and intervention sites in the same city. During phase 1, chlorinated, unfiltered drinking water for both sites was obtained from protected watersheds. During phase 2, the intervention site received chlorinated, filtered and ozonated drinking water. The water was not altered in the control site. No overall differences were found in the risk of any of the illnesses after the new water treatment plant was completed. There was a significantly increased risk of diarrhoea and highly credible gastrointestinal illness in participants with three or more episodes of the same type of illness during phase 1.

Acute pesticide poisoning in the U.S. retail industry, 1998-2004.

OBJECTIVE: This study was conducted to describe the national magnitude and characteristics of acute pesticide poisoning among workers and customers in retail establishments. METHODS: Analyses included retail employees 15-64 years of age and customers with acute pesticide poisoning identified from the Sentinel Event Notification System for Occupational Risks-Pesticides (SENSOR-Pesticides) and California Department of Pesticide Regulation from 1998 to 2004. Pesticide poisoning incidence rates and incidence rate ratios (IRR) were calculated. RESULTS: A total of 325 cases of acute pesticide poisoning were identified. Of these cases, 287 (88%) were retail employees and 38 (12%) were customers. Overall, retail employees had a significantly lower acute pesticide poisoning incidence rate compared with non-agricultural, non-retail employees (IRR=0.53; 95% confidence interval 0.47, 0.59). However, significantly elevated pesticide poisoning incidence rates were observed for four retail occupations (janitors, stock handlers/baggers, bakery/deli clerks, and shipping/receiving handlers). In addition, workers employed in two retail industry sectors (farm supply stores and hardware stores) had significantly elevated acute pesticide poisoning incidence rates. Incidence rates among the retail employees demonstrated a quadratic trend, monotonically decreasing from 1998 to 2000 and monotonically increasing from 2000 to 2003. The rates appear to have leveled off in 2003 and 2004. CONCLUSIONS: Preventive measures to decrease acute pesticide poisoning incidence in the retail sector include adoption of unbreakable and tear-resistant container requirements, increased utilization of integrated pest management strategies, and advisement to store managers, employees, and customers about poisoning prevention.

How clean must our drinking water be: the importance of protective immunity.

BACKGROUND: Cryptosporidium parvum is an important cause of epidemic diarrhea. Few studies have assessed whether serological evidence of prior infection in adults is related to a reduced occurrence of enteric illness. METHODS: Serum samples and enteric illness event data were obtained in 2000 and 2001 from 326 people served by 1 of 2 unfiltered surface sources or 1 groundwater source. In 2001, filtration was initiated at 1 of the surface sources. Poisson regression related illness episodes with serological responses to the 15/17- and 27-kDa Cryptosporidium antigen groups. RESULTS: Subjects with moderately strong responses to the 15/17-kDa antigen had <65% of the risk of all 1-3-day episodes of diarrheal or gastrointestinal illness and <40% of the risk of all >/=4-day episodes, compared with subjects without a moderately strong response. Water source, change in water treatment, and very weak responses were unrelated to illness events. CONCLUSIONS: Endemic Cryptosporidium infections are a common cause of diarrheal and gastrointestinal illness in persons without a moderately strong response to the 15/17-kDa antigen group. Users of surface-derived drinking water are more likely to have strong serological responses to this antigen group and may be at a lower risk of endemic gastrointestinal illness caused by Cryptosporidium infection.

Mortality among children residing near the American Smelting and Refining Company (ASARCO) copper smelter in Ruston, Washington.

A retrospective cohort study was undertaken to determine whether childhood exposure to ambient arsenic was associated with increased mortality rates. Cohort members comprised children who had lived within 4.0 km (2.5 mi) of the American Smelting and Refining Company (ASARCO) copper smelter and arsenic refinery in Ruston, Washington, for at least 2 yr during the time period from 1907 to 1932. The cohort included 1,827 boys and 1,305 girls identified from school census records. Exposure intensity was computed as the total number of years a child had lived at a residence less than 1.6 km (1.0 mi) from the smelter stack during the study period. In only one exposure intensity group (i.e., residence > or = 10.0 yr less than 1.6 km [1.0 mi] from the smelter) for boys were Cox proportional hazards ratios significantly higher than 1.00: for all causes of death (1.52), ischemic heart disease (1.77), and external causes (1.93). For girls, hazard ratios were not elevated significantly for any cause of death in any exposure intensity group.