Measurements of oxygen concentration of air within totally encapsulating chemical-protective suits.

This study measured oxygen concentrations of air within totally encapsulating chemical-protective (TECP) suits during simulated hazardous materials emergency response operations. This was done to allow assessment of the suitability of use of air within TECP suits as an emergency air supply during escapes from contaminated areas following loss of primary air supply. Samples of air were extracted through a probe installed in TECP suits while the suits were worn during simulated hazardous materials control operations. Data on oxygen concentration were obtained using direct reading equipment and through Orsat analysis of samples. Results indicate that the air within a TECP suit becomes significantly oxygen-deficient soon after the suit is closed, but generally maintains oxygen concentrations somewhat above those known to produce significant physiological effects. However, due to the further reduction of oxygen content inherent in breathing the air within TECP suits, it is anticipated that symptoms of oxygen deficiency sufficient to impair escape could be experienced in some instances. Recommendations are made for modifying current training practices to better prepare personnel working in Level A chemical-protective ensembles to cope with loss of air supply.

The effects on mortality of the use of combined oral contraceptives.

OBJECTIVE: To assess, using a computerised model, the effects on mortality of the use of combined oral contraceptives (COCs). DESIGN: Two hypothetical cohorts of one million women each, identical except for their use of contraception. The impact of COC use was explored by applying, to each cohort, death rates which were adjusted according to a series of assumptions about the risks associated with COC use. The model also explored the effects of a number of different patterns of COC use. SETTINGS AND SUBJECTS: Women aged 16, followed through to ages 50 and 75, exposed to 1994 UK death rates. MAIN OUTCOME MEASURES: Numbers of deaths from various cancers and cardiovascular diseases attributable to COC use. RESULTS: Based on the standard pattern of use, there were 1.7 per cent more deaths in the COC cohort to age 50. The important effects on mortality of different patterns of use and of different assumptions about risks in ex-users were illustrated. CONCLUSIONS: The results confirm the findings of earlier work and provide some reassurance about the likely adverse effects of COC use.

PIP: A computer model that takes account of state-of-the-art knowledge about the health risks and benefits of combined oral contraceptive (OC) use was applied to two hypothetical cohorts of 1 million women each aged 16 years and followed through to ages 50 and 75 years, exposed to 1994 UK death rates, who were identical except for contraceptive use. The effects of OC use were examined in relation to deaths from five cancers (ovarian, breast, cervical, endometrial, and liver), cardiovascular diseases (acute myocardial infarction, cerebral thrombosis, venous thromboembolism, and subarachnoid hemorrhage), and deaths associated with IUD use and sterilization. Among the five patterns of OC use included in the model, the standard was OC use from 16 to 29 years, IUD use from 30 to 39 years, and sterilization at age 40 years. Based on the standard pattern of use and standard risk assumptions, the number of deaths in the OC cohort at age 50 years was 1.7% higher than that in the control group, corresponding to an extra 465 deaths by age 50 years in a group of 1 million 16 year olds. To age 75 years, the number of deaths in the OC cohort was 0.5% lower than in the control group, corresponding to a benefit of 735 lives. The total number of deaths in the OC cohort compared to the control group ranged from an increase of 0.2-12.1% to age 50 years and from a decrease of 1.3% to an increase of 0.5% to age 75 years. Analysis of the standard set of assumptions against the standard pattern of use resulted in 22 fewer maternal deaths in the OC cohort than the control group. Although more research is needed on the implications of OC use well into the fifth decade of life, these results provide some reassurance about the likely adverse effects of OC use.

Methicillin-resistant Staphylococcus aureus (MRSA) in nursing homes in a major UK city: an anonymized point prevalence survey.

An anonymized point-prevalence survey of methicillin-resistant Staphylococcus aureus (MRSA) carriage was conducted amongst a stratified random sample of nursing home residents in Birmingham, UK, during 1994. Microbiological sampling from noses, fingers and the environment was undertaken. Information about potential risk factors for the acquisition of MRSA was gathered. MRSA was isolated from cultures of the nose or fingers of 33 of the 191 residents who took part in the study (17%) but only 1 of the 33 positive residents had a clinical infection. Although just 10 of the 87 environmental samples were MRSA positive, there was some environmental contamination in most homes. Risk factors for MRSA carriage were hospital admission within the last year (relative prevalence 2.09, 95% CI 1.13-3.88; P < 0.05) and surgical procedures within the last year (relative prevalence 4.02, 95% CI 2.18-7.43; P = 0.002). Phage-typing of the strains revealed similarities with those circulating in Birmingham hospitals. These findings suggest that the prevalence of MRSA in nursing homes in Birmingham was high, and that the strains may have originated in hospitals.