A risk assessment approach to DDE exposure based on the case of the eastern screech-owl (Megascops asio) in apple orchards of southern Quebec,Canada.

As part of a larger study assessing exposure of the Eastern screech-owl to pesticides in apple orchards from consumption of contaminated small-mammal prey, we evaluated the potential for owls in orchards of southern Quebec to be exposed to persistent contaminants with emphasis on DDE. Levels were highest in short-tailed shrews (0.94 to 26.29 microg/g wet wt). Based on a worst-case scenario, it is possible that consumption of small-mammal prey in orchards of the study area may result in exposure to DDE at a level associated with significant eggshell thinning; however, consumption of other prey, (e.g., robins) may represent a more important threat. Other organochlorines and persistent contaminants such as trace metals and PCBs, reported elsewhere, were found at negligible levels only. Based on an evaluation of the data used, we identify critical information required to enhance the proposed risk assessment.

A case management approach to immunizing patients at high risk for influenza.

The influenza season affects not only the people afflicted with influenza, but the healthcare system as a whole. An estimated dollar 12 billion is the annual cost to care for these patients. An existing problem is that although there is an immunization for influenza, many patients at high risk are not immunized. This article will describe an innovative program of a large Midwest suburban hospital to immunize patients at high risk.

Early sexual activity of delinquent adolescents.

Sexual experiences of 1255 adolescents admitted to a juvenile detention facility were assessed through their responses to a health history questionnaire. More than 80% reported sexual experience. Age at first intercourse acknowledged by females was early (mean 13 years) but rarely prepubertal and was similar for blacks and nonblacks. Males commonly reported beginning sexual experience before age 10 years (40% in blacks and 20% in nonblacks). Sexual activity continued in most, with 73% of the sexually experienced teens reporting intercourse in the month prior to admission. Reports of recent sexual activity increased with age in all race/gender groups. For females, 26% reported sexual misuse compared to 2% of the males. Willingness to answer questions about sexual experiences varied with the question and increased with age. Prepubertal sexual activity is a more common phenomenon than is generally acknowledged. To what extent the experiences reported in our study represent the norm for behavior among individuals of similar background requires further study.

PIP: Sexual experiences of 1255 adolescents admitted to a juvenile detention facility were assessed through their responses to a health history questionnaire. More than 80% reported sexual experience. Age at 1st intercourse acknowledged by females was early (mean 13 years) but rarely prepubertal and was similar for blacks and nonblacks. Males commonly reported beginning sexual experience before age 10 years (40% in blacks and 20% in nonblacks). Sexual activity continued in most, with 73% of the sexually experienced teens reporting intercourse in the month prior to admission. Reports of recent sexual activity increased with age in all race/gender groups. For females, 26% reported sexual misuse compared to 2% of the males. Willingness to answer questions about sexual experiences varied with the question and increased with age. Prepubertal sexual activity is a more common phenomenon than is generally acknowledged. To what extent the experiences reported in our study represent the norm for behavior among individuals of similar background requires further study. This information is derived from a record review of juveniles who presented between May 1981 and September 1986 to a facility serving 11 rural and suburban North Central Florida counties.

Effects of oil and gas well-drilling fluids on the biomass and community structure of microbiota that colonize sands in running seawater.

Well-drilling fluid and a number of the known components (barite, clay, Aldacide, Surflo, and Dowicide, were tested for effects on the biomass and community structure of the microbiota that colonize marine sands exposed for eight weeks to running ambient seawater. Shading the microbiota from light depressed the microflora without a significant effect on the biomass, while well-drilling fluids layered on the surface or mixed with the sand significantly increased a component of the bacteria and the microfauna as reflected in changes in the fatty acid composition. There were some shading effects from the surface layering of well-drilling fluids as reflected in the fatty acids from the microflora when compared to the sands mixed with well-drilling fluids. Barite had essentially no effect on the biomass or community structure while clays increased nearly all of the biomass indicators for the bacteria as well as the microfauna; the clay overlay mirrors the effect of the drilling fluids. Aldacide shifted the bacterial composition, depressing the proportions of microbes containing the cyclopropane fatty acids and the anaerobic pathways of desaturation. Concentrations of 1 and 15 microgram/L increased the bacterial biomass as reflected in the total lipid (16:0) and extractable lipid phosphate coupled with a decrease in the total microeukaryotes. Surflo increased the biomass and shifted the bacterial community structure at concentrations between 4 and 800 microgram/L. The lowest level also stimulated the microfauna. Dowicide at 100 microgram/L increased the bacteria forming cis-vaccenic acid and the microfauna similar to low concentrations of Surflo.

Effect of silicate grain shape, structure, and location on the biomass and community structure of colonizing marine microbiota.

Microbiota colonizing silica grains of the same size and water pore space, but with a different microtopography, showed differences in biomass and community structure after 8 weeks of exposure to running seawater. The absence of surface cracks and crevices resulted in a marked diminution of the total microbial biomass measured as lipid phosphate and total extractable palmitic acid. With increasing smoothness of the sand grain surface, examination of the community structure showed a marked decrease in procaryotes and algal microeucaryotes, with a relative increase in microeucaryotic grazers. A comparison of the colonizing sediment incubated in running seawater or at 32 m on the sea floor with a sediment core showed a decreased bacterial biomass with a different community structure and a decreased total microeucaryotic population of both grazers and algae. The quantitative differences in microbial biomass and community structure between the microcosms and the actual benthic population in the core were determined.