Why are rates of asthma, autism, birth defects, cancer, obesity, and other diseases still increasing among U.S. children? Answers could be found in a redesigned National Children's Study entailing a confederation of regional, prospective birth-cohort studies.

A cross-sectional medical evaluation was conducted to determine respiratory and dermatological effects of platinum salts sensitization among workers in a secondary refinery of precious metals. Fifteen of 107 current employees and eight (28%) of 29 former employees, who had been terminated from employment on average for 5 years because of respiratory symptoms, had positive skin reactivity to platinum salts. Platinum salts skin reactivity was significantly associated with average air concentrations of platinum salts in employees' present work area. Workers with positive platinum salts skin tests had significantly higher prevalences of reported rhinitis, asthma, and dermatitis than negative skin test workers. They also had increased bronchial response to cold air challenge and elevated levels of total serum IgE. Platinum salts sensitization was not associated with atopic tendency as measured by sensitivity to common aeroallergens, but was strongly associated with cigarette smoking status. The findings indicate that cigarette smoking may be a risk factor for the development of platinum salts allergy. The persistence of platinum salts sensitization and high prevalence of adverse health outcomes among former workers demonstrate the importance of regular medical monitoring so that sensitized workers can be removed from exposure before they develop long-term health problems.

An investigation of a platinum refinery operation consisted of an administered questionnaire, spirometry, skin prick testing with platinum salts and common aeroallergens, serum total IgE, radioallergosorbent test for platinum salts, and measurement of nonspecific airway hyperresponsiveness by cold air challenge testing. Among 136 employees examined, there were 107 current and 29 medically terminated workers; 23 (17 percent) subjects had a positive platinum salts prick skin test and 19 (14 percent) displayed a positive cold air challenge. RAST binding for platinum salts IgE antibodies showed a high level of agreement with platinum skin prick test results. A proportion (63 percent) of the population (74 current and 12 terminated workers) underwent repeat platinum skin testing one year later. Among current workers, there was conversion of the platinum skin test from negative to a positive test in five employees, with three conversions occurring in workers who showed only a positive cold air challenge test the year before. Platinum skin sensitivity, asthma symptoms, and nonspecific airway hyperresponsiveness persisted for years after termination of exposure in some medically terminated workers presumably because of a delay in removal from work of employees who became sensitized to platinum salts. It is suggested that proper surveillance for occupational asthma involves the use of several testing procedures. Prompt removal from work of individuals found to become sensitized to platinum salts is important in this industry.