The complex enterprise of modelling prenatal exposure to cigarettes: what is ‘enough’?

While there is a burgeoning body of research linking smoking during pregnancy to problem behaviour in offspring, a major criticism of this work has been the crude measurement of exposure in these studies (e.g. retrospective, self-reported only) that could lead to biased estimates. To address this issue, we used a pregnancy cohort with repeated prospective measures of exposure as well as biological assays to generate estimates of exposure patterns using a range of modelling techniques. In this paper we report on the analytical approaches we have developed, including patterns of exposure over time and best-estimate approaches that combine self-report and cotinine measures, and compare their predictive value in relation to different dimensions of fetal growth as a first step towards examining the utility of greater precision of exposure measurement.
Surprisingly, in this sample the more complex assessments of exposure, including biological measures, generally did not perform better than simple indicators of exposure based on repeated self-report measures, with one exception: a combined self-report cotinine 'best estimate' of third trimester exposure was uniquely associated with lower brain : body ratio. Further study is needed using more sophisticated cotinine assays and testing prediction of a range of outcomes to ascertain whether these findings represent true differences or are specific to the sample, methods and outcomes used. Such research will inform the development of guidelines for adequate exposure characterisation in developmental studies.     

Microbial penetration of gloves following usage in routine dental procedures.

Unsterile polyvinyl, regular latex, and powder-free, modified latex examination gloves were evaluated following usage in routine dental procedures to assess their loss of integrity. Glove fingers were filled with a suspension of red-pigmented Serratia marcescens and drawn across the surface of tryptic soy agar plates. The appearance of red-pigmented Serratia colonies on the plates was used as an indication of glove defects. Unused, unwashed gloves taken at random from boxes served as controls. Of the gloves used in clinical procedures, 83.3% of the polyvinyl gloves, 35.0% of the regular latex gloves, and 7.5% of the powder-free, modified latex gloves allowed penetration of Serratia. Data thus suggest that advances in technology continue to develop a glove with more resistance than regular latex and vinyl gloves to routine clinical usage.     

A cross-sectional study of health complaints among 79 data entry operators using video display terminals

This paper reports on the findings of a cross-sectional study of 79 data entry clerks employed by an Ontario-based organization in five separate offices. The study was conducted to identify factors associated with physical complaints experienced by these office workers. A large percentage of the data entry clerks reported chronic physical complaints (eyestrain, musculo-skeletal pains, headache) as well as emotional or mental stress which they felt were associated with their occupation. Poorly designed overhead lighting systems in all offices contributed to both eyestrain and headache. Duration of employment as a data entry operator within the organization was not associated with stress or physical health complaints. The presence of an adjustable workstation did not in itself guarantee any protection from these conditions. Highly significant associations between occupational stress levels and some physical complaints were observed. The presence of these associations indicated that the management of both physical and stress complaints within these office environments should be tackled simultaneously.