Background Inorganic mercury is toxic to the nervous system, kidneys, and reproductive system. We studied the health effects of mercury exposure among former employees of a chloralkali plant that operated from 1955 to 1994 in Georgia. Methods Former plant workers and unexposed workers from nearby employers were studied. Exposure was assessed with a job‐exposure matrix based on historical measurements and personnel records. Health outcomes were assessed with interviews, physical examinations, neurological and neurobehavioral testing, renal function testing, and urinary porphyrin measurements. Exposure–disease associations were assessed with multivariate modeling. Results Exposed workers reported more symptoms, and tended toward more physical examination abnormalities, than unexposed workers. Exposed workers performed worse than unexposed subjects on some quantitative tests of vibration sense, motor speed and coordination, and tremor, and on one test of cognitive function. Few findings remained significant when exposure was modeled as a continuous variable. Neither renal function nor porphyrin excretion was associated with mercury exposure. Conclusions Mercury‐exposed chloralkali plant workers reported more symptoms than unexposed controls, but no strong associations were demonstrated with neurological or renal function or with porphyrin excretion. Am. J. Ind. Med. 39: 1–18, 2001. © 2001 Wiley‐Liss, Inc.

ABSTRACT. Context. Preventing loss of vaccine potency during storage and handling is increasingly important as new, more expensive vaccines are introduced, in at least 1 case requiring a different approach to storage. Little information is available about the extent to which staff in private physicians' offices meet quality assurance needs for vaccines or have the necessary equipment. Although the National Immunization Program at the Centers for Disease Control and Prevention (CDC) in 1997 developed a draft manual to promote reliable vaccine storage and to supplement published information already available from the CDC and the American Academy of Pediatrics, the best ways to improve vaccine storage and handling have not been defined.Objectives. To estimate the statewide prevalence of offices with suboptimal storage and handling, to identify the risk factors for suboptimal situations in the offices of private physicians, and to evaluate whether the distribution of a new National Immunization Program draft manual improved storage and handling practices.Design. Population-based survey, including site visits to a stratified, random sample of consenting private physicians' offices. At least 2 months before the site visits, nearly half (intervention group) of the offices were randomly selected to receive a draft CDC manual entitled, "Guideline for Vaccine Storage and Handling." The remainder was considered the control group. Trained graduate students conducted site visits, all being blinded to whether offices were in the intervention or control groups. Each site visit included measurements of refrigerator and freezer temperatures with digital thermometers (Digi-thermo, Model 15-077-8B, Control Company, Friendswood, TX; specified accuracy ؎ 1°C). Their metaltipped probes were left in the center shelf of cold storage compartments for at least 20 minutes to allow them to stabilize. The type of refrigerator/freezer unit, temperature-monitoring equipment, and records were noted, as were the locations of vaccines in refrigerator and freezer, and the presence of expired vaccines. Other information collected included the following: staff training, use of written guidelines, receipt of vaccine deliveries, management of problems, number of patients, type of office, type of medical specialty, and the professional educational level of the individual designated as vaccine coordinator. Offices that adhered to daily temperature monitoring for all vaccine cold storage compartments, compared with those that did not, were 2 to 3 times more likely to assign this task to staff with higher levels of training, have received a recent visit from the state immunization program, and be affiliated with a hospital or have Federally Qualified Health Center status. In addition, sites using >1 refrigerator/freezer for vaccine storage were more likely to have at least 1 cold storage compartment outside recommended temperature ranges. We found no significant differences in the data reported above between the intervention group (received copy of the d...

Medicare data represent a valid resource for supplementing state cancer registries in surveillance efforts. This potential is especially applicable to cancers predominantly diagnosed and treated outside the hospital setting.

Chelation challenge testing has been used to assess the body burden of various metals. The best-known example is EDTA challenge in lead-exposed individuals. This study assessed diagnostic chelation challenge with dimercaptosuccinic acid (DMSA) as a measure of mercury body burden among mercury-exposed workers. Former employees at a chloralkali plant, for whom detailed exposure histories were available (n = 119), and unexposed controls (n = 101) completed 24-hr urine collections before and after the administration of two doses of DMSA, 10 mg/kg. The urinary response to DMSA was measured as both the absolute change and the relative change in mercury excretion. The average 24-hr mercury excretion was 4.3 microg/24 hr before chelation, and 7.8 microg/24 hr after chelation. There was no association between past occupational mercury exposure and the urinary excretion of mercury either before or after DMSA administration. There was also no association between urinary mercury excretion and the number of dental amalgam surfaces, in contrast to recent published results. We believe the most likely reason that DMSA chelation challenge failed to reflect past mercury exposure was the elapsed time (several years) since the exposure had ended. These results provide normative values for urinary mercury excretion both before and after DMSA challenge, and suggest that DMSA chelation challenge is not useful as a biomarker of past mercury exposure.