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Recent animal and human studies suggest that prenatal exposure to carcinogens may increase the risk of childhood malignancy. The Texas Childhood Cancer Study (1976-1977) was designed to test the hypothesis that parental exposure to hydrocarbon-related occupations or industries increases this risk. The study subjects, parents of children with and without cancer, were questioned about their job histories. Parents of 296 children with cancer were not exposed to hydrocarbon-related occupations or industries more often than the uncles and aunts of these children, the parents of neighborhood children, or the parents of 283 children without cancer. During the year before birth, odds ratios for fathers of children seen at a hematology clinic with cancer relative to the uncles of these children (0.93), the fathers of neighborhood children (1.33), and the fathers of children seen at the clinic without cancer (0.50) were not statistically significantly different from 1.00 (p greater than 0.05). This lack of association persisted for the year after birth, the year before diagnosis, and the interval from the year before birth to the year of diagnosis; for different diagnoses; for different ages at diagnosis; and for the industries and occupations of female as well as male parents.

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Increased lead absorption was found in 1972 in 56% of 256 children aged 1 to 18 years who lived within 1.6 km of a lead-emitting ore smeltery in El Paso, Tex. Engineering improvements have subsequently reduced emissions from the smeltery, and levels of lead in air, dust, and soil have declined. To evaluate the impact of these environmental improvements on lead absorption, we conducted a follow-up study in 1977 of blood lead levels in 140 children aged 1 through 18 years who lived within 1.6 km of the smeltery. Mean blood lead levels were found to have decreased from 41.4 to 17.7 microgram/dL in children living within 0.8 km of the plant and from 31.2 to 20.2 microgram/dL in children living at 0.8 to 1.6 km. These data argue for the feasibility of reducing children's lead absorption near primary lead smelteries.

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A nationwide survey of heavy-metal exposure in children living near primary nonferrous metal smelters demonstrated high urine arsenic levels in children living near a copper smelter in Ajo, Arizona. Airborne smelter emissions and drinking water were the apparent sources of exposure. To determine whether increased arsenic absorption had produced adverse health effects, we conducted an evaluation of 132 Ajo children 5 to 18 years old and compared results with those of 47 children from a comparison town with low arsenic exposure. Environmental testing showed that Ajo's municipal water supply contained arsenic in concentrations of 0.09 mg/l (the EPA standard is 0.05 mg/l); arsenic concentrations in dust averaged 342.2 microgram/g. Urine arsenic levels in Ajo children correlated positively with amount of tap-water consumed (r = .32, p less than. 0002) and with distance of residence from the smelter (r = .20, p less than .02). Tap-water drinkers had significantly higher urine arsenic levels than bottled water drinkers (t = 4.21 p less than .001). Mean urine arsenic levels were significantly higher for children in Ajo (4.75 microgram/100 ml) than for children in the comparison town (1.17 microgram/100 ml). Hair arsenic levels correlated poorly with arsenic exposure. Despite the study population's chronic exposure to elevated environmental levels of arsenic, no clinical or hematologic abnormalities attributable to arsenic were found.

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The present system of global surveillance of influenza worked effectively in identifying the importance and character of the Hong Kong variant and informing the world of new developments as they occurred. Many deficiencies still exist in the surveillance system that require attention if it is to serve effectively in guiding future control of influenza. More quantitative data are needed regarding incidence of clinical disease, age- and sex-specific attack rates, character and severity of complications, socio-economic factors influencing mortality and distribution and utilization of influenza vaccines.The most valuable index for global surveillance of influenza is excess mortality due to respiratory causes. A comparison of the mortality experience in England and Wales with that in the USA reveals that sharply defined epidemics of influenza A recurred in both countries at intervals of 2-3 years. Mortality rates in England and Wales were considerably greater than in the USA and excess mortality during influenza epidemics was markedly higher in the former country with a notable exception in 1968-69, when the pandemic due to the Hong Kong variant was much more severe in the USA and the mortality in England and Wales was only slightly increased. Mortality data from many other parts of the world could be made available and would materially enhance the effectiveness of the global influenza surveillance programme.

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