Documents Schnorr, Teresa 4 results

"There is a significant public health concern about the potential effects of occupational exposure to toxic substances on reproductive outcomes. Several toxicants with reported reproductive and developmental effects are still in regular commercial or therapeutic use and thus present potential exposure to workers. Examples of these include heavy metals, organic solvents, pesticides and herbicides, and sterilants, anesthetic gases, and anticancer drugs used in health care. Many other substances are suspected of producing reproductive or developmental toxicity but lack sufficient data. Progress has been limited in identifying hazards and quantifying their potencies and in separating the contribution of these hazards from other etiologic factors. Identifying the causative agents, mechanisms by which they act, and any potential target populations, present the opportunity to intervene and protect the reproductive health of workers. The pace of laboratory studies to identify hazards and to underpin the biologic plausibility of effects in humans has not matched the pace at which new chemicals are introduced into commerce. Though many research challenges exist today, recent technologic and methodologic advances have been made that allow researchers to overcome some of these obstacles. The objective of this article is to recommend future directions in occupational reproductive health research. By bridging interdisciplinary gaps, the scientific community can work together to improve health and reduce adverse outcomes. Key words: communication, environmental exposure, occupational exposure, reproduction, research design, risk factors."(Authors' abstract)

"To determine whether the use of video display terminals (VDTs) is associated with an increased risk of reduced birthweight (RBW) and preterm birth, a cohort of telephone operators who used VDTs at work was compared to a cohort of non-VDT-users. Among 2,430 women interviewed, 713 eligible singleton live births were reported. Exposure was estimated from company records and a representative sample of electromagnetic fields was measured at the VDT workstations. For RBW (< or = 2,800 g), we found no excess risk associated with any VDT use during pregnancy (odds ratio [OR] = 0.9; 95% confidence interval [CI] = 0.5-1.7). For preterm birth (< or = 37 weeks), we similarly found no excess risk (OR = 0.7; 95% CI = 0.4-1.1). The risks estimated did not change substantially when hours working with VDTs were used as exposure variables. By contrast, increased risks were found for several known risk factors for LBW and preterm birth. We conclude that occupational VDT use does not increase the risk of RBW and preterm birth."

A cross sectional study of lead (7439921) exposed and unexposed workers was conducted using a comprehensive panel of immunologic parameters to evaluate the association between lead exposure and changes in the immune system. Studies focused particularly on determining whether the number of CD4+ T-cells was affected by lead exposure. Lead exposed workers were recruited from a large secondary lead smelter in the United States. The final study group included 145 exposed and 84 unexposed workers. The median blood lead level (BLL) was 39 micrograms/deciliter (microg/dl) among the exposed (range 15 to 55microg/dl) and the median among the unexposed group was less than 2microg/dl (range of 2 to 12microg/dl). Median zinc-protoporphyrin (ZPP) was 48 among the exposed and 17.5microg/dl among the unexposed group. No association was found between lead exposure and the percentage of CD4+ T-cells. Even though a significant interaction between age and lead exposure for the absolute number of CD4+ T-cells was noted, this finding may have been related to an increase in lymphocyte count with age in the unexposed population. In exposure response analyses among lead exposed workers, no evidence was found of a significant relationship between the number and percentage of CD4+ cells and estimates of exposure including current blood lead, ZPP, or estimated cumulative lead exposure. Lead exposed workers had a significantly lower percentage of monocytes than unexposed workers, although the magnitude of the difference was small.

Epidemiologic studies investigating the cancer risk associated with using metalworking fluids (MWFs) were reviewed. Results of a comprehensive, systemic survey of the epidemiologic evidence for occupational use of MWFs being associated with cancer of the skin and scrotum, larynx, rectum, pancreas, and bladder by NIOSH and which were included in a NIOSH criteria document for MWFs were presented. Specific studies covered included retrospective cohort mortality and cancer incidence studies of MWF exposed cohorts and associated nested case/control studies, proportionate mortality ratio (PMR) studies, and population based (PB) studies. A case/control study and a cancer incidence study and several case reports suggested MWFs, primarily straight oil MWFs, were associated with increased risk of skin and scrotal cancer. None of three PMR studies found an increased risk for skin and scrotal cancer. A number of cohort, PMR, and PB studies found increased risks for laryngeal and rectal cancer, especially for exposure to straight oil MWFs. Several cohort and PMR studies found increased risks for pancreatic cancer among MWF exposed workers. The strongest evidence was for grinding with synthetic MWFs and machining with straight oil MWFS. Some studies were inconsistent; for example, excess cancer risk was found in black, but not white, workers. One of six PMR studies and several PB case control studies found significant excess risks for bladder cancer after controlling for smoking. Neither of two cohort cancers found an elevated bladder cancer risk; however, both were based on small numbers. The route of MWF exposure was generally through dermal contact or inhalation; however, because of the large sizes of many airborne MWF droplets, gastrointestinal exposure may also have occurred. The authors conclude that increased risks for larynx, rectal, pancreatic, skin and scrotal, and bladder cancer were associated with the use of some types of MWFs. Because of the long latency period for solid organ tumors, the MWF exposures probably occurred before the mid 1970s. The risk of cancer from MWF exposures since the mid 1970s is undetermined because a definitive study of workers entering jobs with MWF exposure during this time period has not yet been performed.