An Epidemiologic Approach to the Study of Aerosolized Florida Red Tides

Very little has been published in the scientific literature on the human health effects of Florida red tide, either as human clinical case reports or formal epidemiologic studies. In addition to the health effects associated with the ingestion of contaminated shellfish, there have been multiple anecdotal reports of respiratory irritation and possible immunologic effects associated with the inhalation of aerosolized Florida red tide. To investigate the human health effects from environmental exposure to red tide toxins, we have formed an interdisciplinary team of scientists. We have created a network of public and environmental health workers who periodically report local conditions as a red tide develops. In addition, we have access to environmental monitoring data as well as data from a surveillance program supported through the Florida Poison Information Network. When a red tide moves onshore where people might be exposed, the team rapidly assembles at the site to collect environmental samples and epidemiologic data. To assess the more long-term effects from environmental exposure to red tide toxins, we are conducting epidemiologic studies involving occupational and sensitive populations who live in areas that are regularly impacted by red tides. Other scientists are evaluating the acute and chronic respiratory effects of red tides and brevetoxins in both rat and sheep models as well as refinement of toxin measurement methodology. These models are being used to refine and validate the biomarkers of brevetoxins exposure as well as explore the pathophysiology of health effects from brevetoxins respiratory exposure. Bolstered by the additional research in rat and sheep models, this interdisciplinary scientific team is exploring the acute and chronic exposures and health effects of aerosolized Florida red tides in animal models and various human populations. In the future, this research can be applied to the understanding of exposure and effects of other aerosolized natural toxins such as cyanobacterial toxins.

A Pilot Study of Microbial Contamination of Subtropical Recreational Waters

Microbial water quality indicators are used to determine whether a water body is safe for recreational purposes. There have been concerns raised about the appropriate use of microbial indicators to regulate recreational uses of water bodies, in particular those located in tropical and sub-tropical environments. This prospective cohort pilot study evaluated the relationship between microbial water quality indicators and public health within two public beaches without known sewage discharge, but with historically high microbial levels for one beach, in subtropical Miami-Dade County (Florida). Monitoring was conducted in three phases: daily water monitoring, beach sand sampling, and spatially intense water sampling. An epidemiological questionnaire from a Los Angeles recreational beach-goer study was used to assess the self-reported swimming-related symptoms and exposures. There was no significant association between the number nor the type of reported symptoms and the different sampling months or beach sites, although persons who returned repeatedly to the beach were more likely to report symptoms. The number of indicator organisms correlated negatively with the frequency of symptoms reported by recreational beach goers. Results of the daily monitoring indicated that different indicators provided conflicting results concerning beach water quality.Larger epidemiologic studies with individual exposure monitoring are recommended to further evaluate these potentially important associations in subtropical recreational waters.

Analytical predictive Bayesian assessment of occupational injury risk: municipal solid waste collectors

Unlike other waste streams, municipal solid waste (MSW) is collected manually, and MSW collection has recently been found to be among the highest-risk occupations in the United States. However, as for other occupational groups, actual total injury rates, including the great majority of injuries not compensated and those compensated by other insurance, are not known. In this article a predictive Bayesian method of assessing total injury rates from available information without computation is presented, and used to assess the actual numbers of musculoskeletal and dermal injuries requiring clinical care of MSW workers in Florida. Closed-form predictive Bayesian distributions that narrow progressively in response to information, representing both uncertainty and variability, are presented. Available information included workers' compensation (WC) data, worker population data, and safety records for one private and one public collection agency. Subjective input comprised epidemiological and medical judgment based on a review of 165 articles. The number of injuries was assessed at 3,146 annually in Florida, or 54 +/- 18 injuries per 100 workers per year with 95% confidence. Further, WC data indicate that the injury rate is 50% higher for garbage collectors specifically, indicating a rate of approximately 80 per 100 workers. Results, though subject to uncertainty in worker numbers and classification and reporting bias, agreed closely with a survey of 251 MSW collectors, of whom 75% reported being injured (and 70% reported illness) within the past 12 months. The approach is recommended for assessment of total injury rates and, where sufficient information exists, for the more difficult assessment of occupational disease rates.

A Feasibility Study of the Evaluation of the Florida Breast Cancer Early Detection Program Using the Statewide Cancer Registry

In Florida, a Center for Disease Control and Prevention (CDC)-funded initiative of the Florida Department of Health has targeted socio-economically disadvantaged women for breast and cervical cancer screening. Since 1995, over 12,000 women aged 50-64, within 200% of the federally defined poverty level, with no health insurance, and living in metropolitan catchment areas in Florida, have been screened by the Florida Breast and Cervical Cancer Early Detection Program (BCCEDP). This was a matched cohort cross-sectional analysis of a cohort study of Florida women with breast cancer using the Florida incident cancer registry, the Florida Cancer Data System (FCDS). The study evaluated the hypothesis that there would be no difference in the stage at diagnosis between breast cancer cases in the BCCEDP-screening program and breast cancer cases not diagnosed in the screening program. After linking the BCCEDP records with the FCDS, BCCEDP-screened cases were matched on gender, age, race, ethnicity, and other variables with five groups of FCDS breast cancer cases not screened by BCCEDP to control for demographic and socio-economic factors. Breast cancer cases diagnosed in BCCEDP were significantly more likely to be diagnosed at later stage than non-BCCEDP breast cancer cases in the five matched groups. The BCCEDP is not purely a screening program since it also caters to symptomatic women in the indigent population, therefore these finding were expected. In fact, 71% of the BCCEDP cases were symptomatic at the time of screening/diagnosis and 53% were late-stage diagnosed. These findings show that BCCEDP is indeed servicing its targeted population of medically under-served and symptomatic women in Florida. Furthermore, despite limitations, this study illustrates the potential collaboration between cancer registries and breast cancer screening programs for quality control purposes.

The risk of death for Jehovah's Witnesses after major trauma

BACKGROUND

Trauma surgeons are faced with life-threatening blood loss in patients such as Jehovah's Witnesses. We assessed and compared the risks of death after major trauma for Jehovah's Witnesses and other religious groups.

METHODS

A retrospective cohort study was conducted between August 1992 and September 1999 in a Level I academic trauma center. Statistical methods included Tukey's one-way analysis of variance, chi2 analysis, and bivariate and multivariate logistic regression analyses.

RESULTS

The cohort consisted of 556 patients: 82 Jehovah's Witnesses (14.7%), 52 Baptists (9.4%), 101 Catholics (18.2%), and 321 patients belonging to other religious groups (57.7%). Mean Injury Severity Scores for 433 patients were 10.3 +/- 9, 8.9 +/- 10, 10.3 +/- 11, and 11.3 +/- 14, respectively. There were no significant differences in mean Injury Severity Scores between religious groups, and no statistically significant associations between religion and Injury Severity Scores were identified. Significant predictors of mortality were age, systolic blood pressure at admission, Glasgow Coma Scale score, and type of trauma. Jehovah's Witnesses were 6% more likely to die after major trauma than Baptists, 20% more likely than Catholics, and as likely as patients from any other religious groups.

CONCLUSION

After controlling for age, race, systolic blood pressure, Glasgow Coma Scale score, and type of trauma, Jehovah's Witnesses have a nonsignificant increased risk of death after major trauma compared with other religious groups.

National Health Interview Survey mortality among US farmers and pesticide applicators

BACKGROUND

The mortality experience of pesticide-exposed workers across the US has not been thoroughly studied.

METHODS

Cox regression mortality analyses adjusted for the complex sample survey design were performed on mortality-linked 1986-1994 National Health Interview Survey (NHIS) data.

RESULTS

Nine thousand four hundred seventy-one farmers and pesticide applicators with 571 deaths were compared to 438,228 other US workers with 11,992 deaths. Age-adjusted risk of accidental death, as well as cancers of the nervous and lymphatic/hematopoietic systems, was significantly elevated in male and female pesticide-exposed workers; breast, prostate, and testicular cancer mortality risks were not elevated.

CONCLUSIONS

Compared to all other workers, farmers and pesticide applicators were at greater risk of accidental mortality. These pesticide-exposed workers were not at an increased risk of cancers possibly associated with exposure to estrogen analogue compounds, but were at an increased risk of hematopoietic and nervous system cancers. NHIS mortality follow-up represents an important occupational health surveillance instrument.

Pulmonary lymphangioleiomyomatosis (LAM): examining oral contraceptive pills and the onset of disease

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare pulmonary disease of women of unknown etiology. Diffuse cystic changes associated with multifocal clusters of smooth muscle-like cells (LAM cells) replace normal lung parenchyma, leading to progressive loss of lung function. Reports of exacerbations of LAM with the use of exogenous estrogens and during pregnancy suggest an association between hormones and clinical deterioration.

OBJECTIVES

To conduct the largest case series to date in order to characterize the demographics of a living cohort of patients with LAM. To evaluate the effect of oral contraceptive pill (OCPs) use on the age at onset of symptoms in a large population of women with LAM.

METHODS

The study population was drawn from the University of Miami (UM) LAM database consisting of 91 living women previously diagnosed with LAM by a physician. A self-administered questionnaire was mailed to the participants.

RESULTS

The final response rate was 91.2% (83 of 91), and the study participants were 96.4% white, 1.2% Asian, 1.2% African American, and 1.2% American Indian; 68.4% identified their ethnicity as European and 14.5% as Jewish. Of the women surveyed, 73 were still menstruating at the time of LAM diagnosis. Among these women, the rate of use of OCPs was approximately 27%, similar to the rate in the general population. There was a significant difference between the age at onset of symptoms in women using OCPs vs. women not using OCPs (29.2 +/- 4.7 vs. 32.9 +/- 8.0, p = 0.0397).

CONCLUSIONS

The present study suggests that OCPs may serve as catalysts to promote an earlier occurrence of LAM.

Cancer among Hispanic women in South Florida: an 18-year assessment: a report from the Florida Cancer Data System

BACKGROUND

The Hispanic population now represents the majority of residents in Miami-Dade County, Florida. The authors present cancer incidence and mortality data for South Florida's Hispanic women for the period 1990-1998 and compare these data to previously reported data from 1981-1989. Cancer incidence, risk, and mortality data should reflect current population distribution, lifestyle, and environmental risk factors so that cancer prevention and control activities are informed optimally.

METHODS

The study population consisted of all women with malignant disease during 1981-1998 from Miami-Dade County found in the Florida Cancer Data System data base; patients were divided into 2 9-year periods for analysis. Age-standardized incidence and mortality rates were computed for common disease sites; rates for Hispanic women were compared with the rates for non-Hispanic white (NHW) women as standardized rate ratios (SRR) with 95% confidence intervals (95%CIs). Incidence and mortality trends were analyzed using linear regression.

RESULTS

Over 70,000 cancer incidents were analyzed. The overall decreased cancer risk for Hispanic women (SRR, 0.65; 95%CI, 0.64-0.67), compared with NHW women, remained essentially constant over the two study periods. Cancer incidence increased similarly for the two racial-ethnic groups. The incidence of lung carcinoma increased in both groups, becoming the second most common disease site for NHW women and the third most common disease site for Hispanic women.

CONCLUSIONS

The decreased relative cancer risk for Hispanic women in South Florida has remained stable over the past 18 years. Lung carcinoma is increasing among women in both racial-ethnic groups.

Influence of structured encounter forms on documentation by community pediatricians

BACKGROUND

Age-specific structured encounter forms for well-child examinations have been shown to improve thoroughness of documentation among pediatric house staff. This study evaluated the influence of such forms on completeness of documentation by practicing pediatricians.

METHODS

In this before-after trial at 5 urban community health clinics, participants were 8 pediatricians practicing for at least 1 year. Brief group training sessions on use of the forms were provided to the participating physicians. Completeness of documentation was defined as the proportion of elements from a full well-child examination recorded in the medical record.

RESULTS

After introduction of the standardized forms, completeness of documentation significantly increased for all components.

CONCLUSIONS

The use of age-specific structured encounter forms improved the completeness of documentation of pediatric well-child examinations done by pediatricians.

Indicators of ocean health and human health: developing a research and monitoring framework

We need to critically assess the present quality of the marine ecosystem, especially the connection between ecosystem change and threats to human health. In this article we review the current state of indicators to link changes in marine organisms with eventual effects to human health, identify research opportunities in the use of indicators of ocean and human health, and discuss how to establish collaborations between national and international governmental and private sector groups. We present a synthesis of the present state of understanding of the connection between ocean health and human health, a discussion of areas where resources are required, and a discussion of critical research needs and a template for future work in this field. To understand fully the interactions between ocean health and human health, programs should be organized around a "models-based" approach focusing on critical themes and attributes of marine environmental and public health risks. Given the extent and complex nature of ocean and human health issues, a program networking across geographic and disciplinary boundaries is essential. The overall goal of this approach would be the early detection of potential marine-based contaminants, the protection of marine ecosystems, the prevention of associated human illness, and by implication, the development of products to enhance human well-being. The tight connection between research and monitoring is essential to develop such an indicator-based effort.

Cancer trends among Hispanic men in South Florida, 1981-1998

BACKGROUND

Hispanics now represent a majority of residents in Miami-Dade County, Florida. In this report, the authors present new cancer incidence and mortality data for South Florida's Hispanic men for the period 1990-1998 and compare them with data from a previous report from the 1980s. Periodic updating of cancer incidence data, reflecting current population distribution, lifestyle, and environmental risk factors, is necessary to inform cancer prevention and control activities optimally.

METHODS

The study population consisted of all incidents of cancer (1981-1998) occurring in males from Miami-Dade County, as determined from the Florida Cancer Data System data base; patients were divided into two 9-year periods for analysis. Age-standardized incidence and mortality rates were computed for 14 common cancer sites, and rates for Hispanic men were compared with the rates for non-Hispanic white men as standardized rate ratios (SRRs) with 95% confidence intervals (95% CIs). Incidence and mortality trends were determined using linear regression analysis.

RESULTS

Nearly 70,000 incident cancer cases were analyzed. For 1990-1998, the top five incident cancers for both race/ethnic groups were the same. The overall decreased cancer risk for Hispanic men (SRR, 0.80; 95% CI, 0.79-0.82), compared with non-Hispanic white men, remained essentially constant over the two study periods. Cancer incidence increased similarly for the two race-ethnic groups; cancer mortality decreased, with a sharper decrease for non-Hispanic white men, resulting in apparent convergence of mortality trends recently.

CONCLUSIONS

Differences in cancer risk for South Florida's Hispanic men have not attenuated over the past 20 years. With cancer incidence significantly less for Hispanic men, their mortality rate approaches that of non-Hispanic white men, and cancer prevention and control strategies targeted for this ethnic group become increasingly important.

Pilot detection study of alpha(1) antitrypsin deficiency in a targeted population

Screenings for the genetic disorder alpha(1) antitrypsin deficiency (AAT Deficiency) have been one of two models: large screenings of general populations and small targeted detection programs in high-risk groups. The most appropriate screening and detection methodologies in terms of target populations, subject participation and yield of positive tests, however, have not been well defined. The major objective of this pilot study was to evaluate the effectiveness in terms of participation of two different AAT Deficiency detection programs using a self-administered fingerstick blood test. Individuals ages 30-60 under the care of a pulmonary physician and with a diagnosis of emphysema, COPD, chronic bronchitis, or bronchiectasis were the targeted population. Participants were offered AAT Deficiency testing in the pulmonary physician's office compared with testing offered through mail. Participation (i.e., frequency of subject participation in the detection program) of two different AAT Deficiency detection programs. Non-participation was due to fear of self-administered testing and research studies; women were more likely to participate than men. Eligible subjects were significantly more likely to participate when offered testing by their pulmonary physician in-office (83%) than mail-only (42%) (P < 0.02). Although self-administered genetic testing is available, highest participation in AAT Deficiency detection program was found when offered directly by the physician. This finding may have implications for screening and detection of other genetic diseases. Future studies need to evaluate the yield (i.e., frequency of positive tests) of these detection methodologies in highly targeted populations.

Hepatocellular carcinoma incidence in Florida. Ethnic and racial distribution

BACKGROUND

Hepatocellular carcinoma (HCC), the primary form of liver carcinoma, is increasing in incidence worldwide. The increasing numbers of Hispanic immigrants in Florida suggest that the rate of HCC in the Hispanic population should be of special concern. This study describes racial and ethnic distribution and trends of incident HCC in Florida from 1985 to 1995.

METHODS

A total of 2837 cases of incident HCC from 1985 to 1995 were examined from Florida's incident cancer registry, the Florida Cancer Data System. Age standardized and age specific average annual incidence rates were calculated for the state of Florida by gender and by racial and ethnic group.

RESULTS

Over the study period, the average annual incidence HCC rates in Florida among male and female Hispanics and blacks were consistently and significantly twice the rate of white males and females as standardized rate ratios. Males were at least twice as likely to have HCC compared with females in all three racial and ethnic subpopulations.

CONCLUSIONS

The incidence of HCC in Florida was comparable to the overall U.S. incidence with respect to average annual incidence and gender distribution. Florida blacks and Hispanics are at significantly increased risk for HCC incidence compared with Florida whites. These results have implications for preventive HCC recommendations in growing racial and ethnic subpopulations in the United States.

Lymphoma and lymphoid leukemia incidence in Florida children: ethnic and racial distribution

BACKGROUND

Incidence reports for pediatric lymphoma and lymphoid leukemia in Hispanic subpopulations in the United States are rare. The authors hypothesized that Florida's Hispanic children would have higher risks of lymphoma and lymphoid leukemia compared with non-Hispanic white children.

METHODS

All cases of lymphoid leukemia, Hodgkin, non-Hodgkin, and Burkitt lymphoma (SEER International Classification of Diseases for Oncology codes) in children (< 15 years) in the Florida Cancer Data System (FCDS) from 1985 to 1997 were studied. Cases were classified as: 1) white, 2) Hispanic, or 3) black, and stratified by age. Age-adjusted rates for the three race-ethnic groups were calculated. Rates for Hispanics and blacks were compared with whites as standardized rate ratios (SRR) with 95% confidence intervals.

RESULTS

Seven hundred thirty-one incident cases of pediatric lymphoma and 1231 cases of lymphoid leukemia were identified during the study period. For children with lymphoma, the SRR for Hispanics was 1.32 (95% CI, 1.20-1.44), and for blacks, the SRR was 0.68 (95% CI, 0.63-0.72. For lymphoid leukemia, the SRR for Hispanics was 1.29 (95% CI, 1.28-1.30), and for blacks, the SRR was 0.55 (95% CI, 0.54-0.56). Similar rates were found for the Hodgkin and non-Hodgkin subgroups.

CONCLUSIONS

Incidences of Hodgkin and non-Hodgkin lymphoma were significantly higher in Florida's Hispanic children, with 30% increased relative risks, compared with whites. Black children had significantly decreased incidences and risk. Results for lymphoid leukemia were similar. Incidence of lymphoma in Florida's Hispanic children (primarily Cuban and Central American origin) differed from similar reports from Texas and California, where Hispanics are primarily of Mexican origin.

Formation and current results of a patient-organized registry for alpha(1)-antitrypsin deficiency

BACKGROUND

Significant challenges exist to investigating uncommon illnesses because too few patients are seen at any single clinical center to permit appropriate research studies. Recognizing this impediment to clinical research in alpha(1)-antitrypsin deficiency, the Alpha One Foundation, a patient-organized research foundation, has collaborated with clinician-scientists to organize a voluntary registry of individuals with alpha(1)-antitrypsin deficiency.

PURPOSE

To facilitate clinical research in alpha(1)-antitrypsin deficiency by organizing a registry of affected individuals willing to be approached to participate in clinical studies.

METHODS

Elements of the Alpha One Foundation Research Network Registry include a Medical and Scientific Advisory Committee, composed of physician-investigators and patient advocates, designated clinical resource centers at medical institutions with expertise in the management of individuals with alpha(1)-antitrypsin deficiency, and a data coordinating center with responsibility for database management and analysis. Questionnaires requesting information about demographic features, alpha(1)-antitrypsin phenotype, smoking history, and health-care utilization were distributed to prospective registrants through the following channels: mailings from the Alpha One Foundation; mailings from the clinical resource centers; and distribution by home-care and pharmaceutical companies. Information from this questionnaire formed the basis of the initial registry database.

RESULTS

Between May 1997 and June 1999, 7,789 forms were distributed, and forms were returned by 712 unique registrants. Registrants have the following characteristics: mean (+/- SD) age, 49.3+/-13.2 years; women, 47.7%; white, 96.2%; PI*ZZ phenotype, 70.7%; ex-smokers, 73.3%; COPD patients, 87.2% (emphysema patients, 54.2%; chronic bronchitis patients, 33%); and self-reported liver disease, 6.4%. The mean number of physician visits reported by registrants in the preceding 12 months was 7.8+/-9.4, 59% reported currently receiving IV augmentation therapy, and 35% reported using supplemental oxygen at home. Examples of ongoing research studies using this unique database include: (1) a case-control study to evaluate occupational risk factors for obstructive lung disease in individuals with alpha(1)-antitrypsin deficiency and (2) a study to evaluate the health-care costs for affected individuals.

CONCLUSIONS

A registry currently including 712 individuals with alpha(1)-antitrypsin deficiency has been organized through a collaboration between physician-investigators and a patient-organized research foundation. Use of the registry has already facilitated studies that were previously difficult because of the paucity of identifiable study subjects. The registry cohort promises to provide an important resource for future clinical and epidemiologic studies.

Cancer incidence in a cohort of licensed pesticide applicators in Florida

This study is a standardized incidence ratio (SIR) analysis of cancer incidence of licensed pesticide applicators in Florida, compared with that of Florida's general population. Through extensive data linkages, 33,658 applicators were assembled who had 1266 incident cancers and 279,397 person-years from January 1, 1975, to December 31, 1993. Disease risk from ethanol and tobacco use were significantly decreased. Among males, prostate cancer (SIR = 1.91; 95% confidence interval [CI], 1.72-2.13) and testicular cancer (SIR = 2.48; 95% CI, 1.57-3.72) were significantly elevated. No confirmed cases of soft tissue sarcoma (STS) were found, and the incidence of non-Hodgkin's lymphoma was not increased. There were few female applicators; nevertheless, cervical cancer incidence (SIR = 3.69; 95% CI, 1.84-6.61) was significantly increased, while the incidence of breast cancer was significantly decreased. Cancers that have been associated with estrogen disrupters were found in male, but not female, pesticide applicators. The lack of soft tissue sarcoma is at odds with prior literature associated with the use of phenoxy herbicides.

Mortality in a cohort of licensed pesticide applicators in Florida

OBJECTIVES

Although the primary hazard to humans associated with pesticide exposure is acute poisoning, there has been considerable concern surrounding the possibility of cancer and other chronic health effects in humans. Given the huge volume of pesticides now used throughout the world, as well as environmental and food residue contamination leading to chronic low level exposure, the study of possible chronic human health effects is important.

METHODS

This was a retrospective cohort study, analysed by general standardised mortality ratio (SMR) of licensed pesticide applicators in Florida compared with the general population of Florida. A cohort of 33,658 (10% female) licensed pesticide applicators assembled through extensive data linkages yielded 1874 deaths with 320,250 person-years from 1 January 1975 to 31 December 1993.

RESULTS

The pesticide applicators were consistently and significantly healthier than the general population of Florida. As with many occupational cohorts, the risks of cardiovascular disease and of diseases associated with alcohol and tobacco use were significantly lower, even in the subpopulations--for example, men, women, and licence subcategories. Among male applicators, prostate cancer mortality (SMR 2.38 (95% confidence interval (95% CI) 1.83 to 3.04) was significantly increased. No cases of soft tissue sarcoma were confirmed in this cohort, and non-Hodgkin's lymphoma was not increased. The number of female applicators was small, as were the numbers of deaths. Mortality from cervical cancer and breast cancer was not increased. Additional subcohort and exposure analyses were performed.

CONCLUSIONS

Consistent with previous publications on farmers but at odds with current theories about the protective effects of vitamin D, prostate cancer was increased in these pesticide applicators. Female breast cancer was not increased despite theories linking risk of breast cancer with exposure to oestrogen disruptors--such as the organochlorines. The lack of cases of soft tissue sarcoma is at odds with previous publications associating the use of the phenoxy herbicides with an increased risk of these cancers.

Health effects associated with sulfuryl fluoride and methyl bromide exposure among structural fumigation workers

OBJECTIVES

This study assessed the health effects associated with occupational exposure to methyl bromide and sulfuryl fluoride among structural fumigation workers.

METHODS

A cross-sectional study of 123 structural fumigation workers and 120 referents in south Florida was conducted. Nerve conduction, vibration, neurobehavioral, visual, olfactory, and renal function testing was included.

RESULTS

The median lifetime duration of methyl bromide and sulfuryl fluoride exposure among workers was 1.20 years and 2.85 years, respectively. Sulfuryl fluoride exposure over the year preceding examination was associated with significantly reduced performance on the Pattern Memory Test and on olfactory testing. In addition, fumigation workers had significantly reduced performance on the Santa Ana Dexterity Test of the dominant hand and a nonsignificantly higher prevalence of carpal tunnel syndrome than did the referents.

CONCLUSIONS

Occupational sulfuryl fluoride exposures may be associated with subclinical effects on the central nervous system, including effects on olfactory and some cognitive functions. However, no widespread pattern of cognitive deficits was observed. The peripheral nerve effects were likely caused by ergonomic stresses experienced by the fumigation workers.

Race-specific cancer mortality in US firefighters: 1984-1993

A mortality odds ratio (MOR) study of race-specific cancer risk among firefighters was conducted using 1984-1993 death certificate data from 24 states. The Bureau of the Census Index of Industries and Occupations was used to code occupation on death certificates. The overall cancer mortality was slightly elevated among white firefighters (MOR = 1.1; 95% confidence interval [CI] = 1.1-1.2), but the increase in overall cancer mortality among black firefighters was not significant (MOR = 1.2; 95% CI = 0.9-1.5). Only prostate cancer risk was elevated in both groups (whites: MOR = 1.2; 95% CI = 1.0-1.3; blacks: MOR = 1.9; 95% CI = 1.2-3.2). Among white firefighters, elevated site-specific cancer mortality risks were found for the following cancer sites: lip (MOR = 5.9; 95% CI = 1.9-18.3), pancreas (MOR = 1.2; 95% CI = 1.0-1.5), soft tissue sarcoma (MOR = 1.6; 95% CI = 1.0-2.7), melanoma (MOR = 1.4; 95% CI = 1.0-1.9), kidney and renal pelvis (MOR = 1.3; 95% CI = 1.0-1.7), non-Hodgkin's lymphoma (MOR = 1.4; 95% CI = 1.1-1.7), and Hodgkin's disease (MOR = 2.4; 95% CI = 1.4-4.1). We also observed a slightly elevated risk for bronchus and lung cancer (MOR = 1.1; 95% CI = 1.0-1.2). Among black firefighters, excess risks were found for cancers of the brain and central nervous system (MOR = 6.9; 95% CI = 3.0-16.0), colon (MOR = 2.1; 95% CI = 1.1-4.0), and nasopharynx (MOR = 7.6; 95% CI = 1.3-46.4). Future studies are needed to confirm the existence of differential cancer mortality risks among firefighters of different race/ethnic subpopulations.

Genotoxicity in workers exposed to methyl bromide

To address the genotoxicity of in vivo methyl bromide (CAS 74-83-9) exposure in humans, we collected blood and oropharyngeal cells as part of a cross-sectional morbidity study of methyl bromide-exposed fumigation workers and their referents. Micronuclei were measured in lymphocytes and oropharyngeal cells, and hypoxanthine-guanine phosphoribosyl transferase gene (hprt) mutations were measured in lymphocytes. A total of 32 workers and 28 referents provided specimens. Among current non-smokers, mean hprt variant frequencies (Vfs) were found to be elevated among workers compared to referents (geometric mean: workers=4.49x10(-6), referents=2.96x10-(6); two-sided p=0.22); this difference was more pronounced among workers with 4 h or more of recent methyl bromide exposure compared to referents (geometric mean: workers=6.56x10(-6), referents=2.96x10(-6); two-sided p=0.06). Mean oropharyngeal cell micronuclei were higher among workers compared to referents (mean: workers=2.00, referents=1.31; two-sided p=0.08); the results were similar when workers with 4 h or more of recent methyl bromide exposure were compared to referents (mean: workers=2.07, referents=1.31; two-sided p=0.13). No consistent differences between workers and referents were observed for frequencies of kinetochore-negative lymphocyte micronuclei, or kinetochore-positive lymphocyte micronuclei. The study was limited by a sample size sufficient only for detecting relatively large differences, absence of a reliable method to measure the intensity of workplace methyl bromide exposures, and relatively infrequent methyl bromide exposure (e.g., the median length of exposure to methyl bromide during the 2 weeks preceding the survey was 4 h). In conclusion, our findings provide some evidence that methyl bromide exposure may be associated with genotoxic effects in lymphocytes and oropharyngeal cells. Further study on the genotoxicity of methyl bromide exposure in humans is warranted.

Agreement between company-recorded and self-reported estimates of duration and frequency of occupational fumigant exposure

Investigators must often rely on self-reported work history information collected with questionnaires. However, little is known about the agreement between self-reported estimates of exposure and records kept by companies. As part of a cross-sectional medical study of structural fumigation workers, self-reported work history information was collected on both duration and frequency of exposure using an interviewer-administered questionnaire. All company records available on these workers were also collected. Only 15 of 81 structural fumigation companies identified by study participants as current or past structural fumigation employers had records suitable for comparison. These 15 companies employed 32 of the workers who participated in the cross-sectional medical study. The exposure information provided by the 32 workers was compared to information obtained from company records. By examining the agreement between these two data sources, potential limitations were identified in both the self-reported and company-recorded exposure data. By recognizing these limitations in the exposure data, we identified the most appropriate exposure measures to be used in subsequent data analyses. This exercise also demonstrated the difficulties in undertaking these exposure comparisons in an industry consisting of many small, independent companies. Similar difficulties with assessing exposures may be experienced by investigators studying other service industries consisting of many small, independent companies (e.g., dry cleaning, auto repair).

Occupational exposure to inorganic mercury vapour and reproductive outcomes

The effect of exposure to inorganic mercury on the pregnant woman and her foetus has received little attention. Transport of elemental inorganic mercury into foetal tissues has been reported, and prior studies indicate a higher incidence of adverse pregnancy outcome. The effects of occupational exposure to inorganic mercury on pregnancy were investigated among 46 exposed women workers: controls were 19 women working in non-production areas of the same factory. There were 104 recorded total pregnancies during the period 1948-77. The study revealed a higher frequency of adverse reproductive outcomes, especially congenital anomalies, among the women exposed to inorganic mercury levels at or substantially lower than 0.6 mg/m3; no significant differences in the stillbirth or miscarriage rates were noted between the two groups of women. The overall foetal death rate in this study was similar to New York state (USA) and national levels for the same period.

Bloodborne pathogens risk and precautions among urban fire-rescue workers

Health care workers are exposed to various infectious agents that can lead to disease transmission during patient care. Emergency first-responders, paramedics, and emergency medical technicians (EMTs) are a subgroup of health care workers particularly at risk for occupational exposure to bloodborne pathogens. The Centers for Disease Control and Prevention has recommended universal precautions to prevent occupational transmission of bloodborne pathogens among health care workers. This cross-sectional study evaluates risks and behaviors for occupational exposure to bloodborne pathogens among urban paramedics and EMTs in Dade County, Florida. Reported exposure via multiple routes was common, especially among paramedics. Knowledge of universal precautions was high, but reported practices were suboptimal because of inadequate information, as well as logistical and access issues. Additional research, administrative effort, and regulation are needed to increase the application of universal precautions in the prehospital setting.

Aplastic anemia and pesticides. An etiologic association?

The majority of cases of aplastic anemia, a rare previously lethal disease, are of unknown etiology. Nevertheless, for the past 3 decades, case reports and case series of aplastic anemia have suggested an etiologic association between aplastic anemia and pesticide exposure. A review of the medical literature, including basic science literature, confirms a possible etiologic association between pesticide exposure and aplastic anemia. Two hundred and eighty cases of aplastic anemia associated with pesticide exposure were reported in the literature. The majority of these cases were young (mean age, 34 years; median, 28), with a short latency (mean, 5 months) and with a history of occupational exposure to pesticides. The pesticide exposures reported were the organochlorines and organophosphates, both commonly used pesticides throughout the world. Therapeutic and methodologic issues as well as future directions for research into this etiologic association are discussed.

Rapid cocaine screening of urine in a newborn nursery

A rapid cocaine screening test, the Abuscreen OnTrak assay, was compared with the EMIT (enzyme-multiplied immunoassay technique) screening test to determine relative accuracy in 450 newborn infants sequentially tested for urinary cocaine during a 6-week period at a large urban hospital. The Abuscreen Ontrak screen had a sensitivity of 96% and a specificity of 100%.

Unusual occupational gastrointestinal and hepatic disorders

Acute centrolobular necrosis, cancers related to occupational chemical exposures, and infectious hepatitis are widely recognized, but other occupational and environmental diseases of the gastrointestinal tract are underemphasized by comparison. This review explores the associations between workplace exposures and steatosis, increased liver microsomal activity, cholestatic liver injury, portal fibrosis and hepatic sclerosis, granulomatous liver disease, porphyria cutanea tarda, peptic ulcer disease, pancreatitis, gastroenteritis, celiac disease, and pneumatosis cystoides intestinalis.

Disease clusters in occupational medicine: a protocol for their investigation in the workplace

Disease clusters have been an important source of epidemiologic and medical information in the history of occupational medicine. Many accepted disease-exposure linkages were first observed and investigated as disease clusters in the workplace setting. Recent interest in disease cluster methodology has focused on traditional environmental settings. There has been very little work on a similar methodology for the investigation of disease clusters in the workplace, despite the many advantages of workplace cluster investigations for recognizing new etiologic associations. In this paper, a protocol is proposed and discussed which can be implemented in both acute and chronic disease cluster outbreaks in the workplace, where no obvious previously recognized cause is identified. A standardized approach to occupational disease cluster investigation will lead to increased efficiency, decreased social-political tensions, and a greater yield of scientific information.

Liver injury in workers exposed to dimethylformamide

An apparent epidemic cluster of toxic liver disease was reexamined among workers exposed to the solvent dimethylformamide. A demographically similar but unexposed group from a preemployment population was used for comparison. Analysis, after data transformation of the liver transaminases, revealed significant differences between the two populations with respect to the serum glutamic pyruvic transaminase and the ratio of serum glutaminic oxaloacetic transaminase to serum glutamic pyruvic transaminase. Thus a value of the ratio of serum glutamic oxaloacetic transaminase to serum glutamic pyruvic transaminase. Thus a value of the ratio less than 1 may be suggestive of toxic liver disease. Medical surveillance of the working population for 14 months revealed no further cases of toxic liver disease. Dimethylformamide was almost certainly the causative agent of the original epidemic. The use of preemployment populations as a source of unexposed subjects in the analysis of occupational clusters is recommended, especially in the scenario of relatively acute, and highly prevalent, occupational diseases.