Health effects from chronic low-level exposure to hydrogen sulfide.

The acute toxic effects of hydrogen sulfide have been known for decades. However, studies investigating the adverse health effects from chronic, low-level exposure to this chemical are limited. In this study, the authors compared symptoms of adverse health effects, reported by residents of two communities exposed mainly to chronic, low-levels of industrial sources of hydrogen sulfide, to health effects reported by residents in three reference communities in which there were no known industrial sources of hydrogen sulfide. Trained interviewers used a specially created, menu-driven computer questionnaire to conduct a multi-symptom health survey. The data-collection process and questions were essentially the same in the reference and exposed communities. The two exposed communities responded very similarly to questions about the major categories. When the authors compared responses of the exposed communities with those of the reference communities, 9 of the 12 symptom categories had iterated odds ratios greater than 3.0. The symptoms related to the central nervous system had the highest iterated odds ratio (i.e., 12.7; 95% confidence interval = 7.59, 22.09), followed by the respiratory category (odds ratio = 11.92; 95% confidence interval = 6.03, 25.72), and the blood category (odds ratio = 8.07; 95% confidence interval = 3.64, 21.18). Within the broader health categories, individual symptoms were also elevated significantly. This study, like all community-based studies, had several inherent limitations. Limitations, and the procedures the authors used to minimize their effects on the study outcomes, are discussed. The results of this study emphasize the need for further studies on the adverse health effects related to long-term, chronic exposure to hydrogen sulfide.

Amphotericin B lipid complex for the treatment of patients with acute leukemia and hepatosplenic candidiasis.

Hepatosplenic candidiasis (HSC) is an emerging complication of the treatment of patients with acute leukemia. Treatment of this infection can be very difficult and data on the duration of antifungal therapy are not available. We evaluated the efficacy of amphotericin B lipid complex (ABLC) for the treatment of five patients with acute leukemia and HSC. The dose of the administered ABLC ranged between 5 and 11 mg/kg per day and the median duration of therapy was 4.3 months. Four patients had complete response to the above treatment with resolution of fever and improvement in the radiologic findings. One patient refused to continue treatment and subsequently died with relapsed leukemia and disseminated Candida infection. Preliminary data suggest that ABLC is a well-tolerated and effective treatment for HSC and should be considered for phase II trials as front line treatment for this type of deep seated fungal infections.

The health effects of living near cement kilns; a symptom survey in Midlothian, Texas.

Cement kilns are major sources of toxic air emissions. Regulations based on demonstrated concentrations of specific chemicals, and risk assessments with inherent limitations and uncertainties, are the current methods of preventing exposure to 'unsafe' emission levels. Monitoring data are frequently incomplete. These limitations mandate that residents residing near cement kilns be evaluated for adverse health effects. This study reports findings from a symptom survey conducted in Midlothian, Texas, which adds to the limited but growing body of knowledge showing that persons living near cement kilns are experiencing increased respiratory effects. This cross-sectional study uses randomized sampling and an extensive health questionnaire, covering 12 physiological systems, to determine differences in reported health symptoms between the study community (Midlothian, Texas, n = 58) and the reference community (Waxahachie, Texas, n = 54). Findings indicate significant elevations in reported respiratory symptoms in the study community (p-value 0.002). Although the comparatively small sample size is a limitation, the fact that only 'respiratory effects' were highly significant supports the efficacy of this investigation. Respiratory effects would be the major anticipated outcome from the known exposures under investigation. This specificity of response (i.e., elevation in respiratory symptoms only), indicates that 'response bias' was not a significant factor in this study.