Asbestos and Other Hazardous Fibrous Minerals: Potential Exposure Pathways and Associated Health Risks.

There are six elongate mineral particles (EMPs) corresponding to specific dimensional and morphological criteria, known as asbestos. Responsible for health issues including asbestosis, and malignant mesothelioma, asbestos has been well researched. Despite this, significant exposure continues to occur throughout the world, potentially affecting 125 million people in the workplace and causing thousands of deaths annually from exposure in homes. However, there are other EMPS, such as fibrous/asbestiform erionite, that are classified as carcinogens and have been linked to cancers in areas where it has been incorporated into local building materials or released into the environment through earthmoving activities. Erionite is a more potent carcinogen than asbestos but as it is seldom used for commercial purposes, exposure pathways have been less well studied. Despite the apparent similarities between asbestos and fibrous erionite, their health risks and exposure pathways are quite different. This article examines the hazards presented by EMPs with a particular focus on fibrous erionite. It includes a discussion of the global locations of erionite and similar hazardous minerals, a comparison of the multiple exposure pathways for asbestos and fibrous erionite, a brief discussion of the confusing nomenclature associated with EMPs, and considerations of increasing global mesothelioma cases.

Outcomes of a Survey-Based Approach to Determine Factors Contributing to the Shortage of Occupational Medicine Physicians in the United States.

CONTEXT: There is a long-standing shortage of formally trained Occupational & Environmental Medicine (OEM) physicians despite OEM practitioners experiencing high satisfaction and low burnout. OBJECTIVE: To explore the root causes of this shortage and suggest potential remedies. METHODS: Cross-sectional surveys were administered to medical students queried regarding OEM training, practicing OEM physicians queried regarding timing of specialty choice, and OEM Train-in-Place (TIP) program graduates queried regarding satisfaction with training. RESULTS: Of 247 medical student respondents, 70% had heard of OEM, 60% through one lecture. Of the 160 OEM physicians, 17% first became aware of OEM as medical students, and most would have chosen a different path had they heard sooner. Most TIP program trainees reported that they would not have undertaken specialty training without a TIP program (89%). CONCLUSIONS: Strategies to introduce OEM earlier in medical education and TIP programs for mid-career physicians may help overcome persistent shortages of OEM specialists.

Ascertainment Bias in a Historic Cohort Study of Residents in an Asbestos Manufacturing Community.

This paper describes follow-up for a cohort of 4530 residents living in the asbestos manufacturing community of Ambler, PA, U.S. in 1930. Using re-identified census data, cause and date of death data obtained from the genealogic website Ancestry.com, along with geospatial analysis, we explored relationships among demographic characteristics, occupational, paraoccupational and environmental asbestos exposures. We identified death data for 2430/4530 individuals. Exposure differed significantly according to race, gender, age, and recency of immigration to the U.S. Notably, there was a significant difference in the availability of year of death information for non-white vs. white individuals (odds ratio (OR) = 0.62 p-value < 0.001), females (OR = 0.53, p-value < 0.001), first-generation immigrants (OR = 0.67, p-value = 0.001), second-generation immigrants (OR = 0.31, p-value < 0.001) vs. non-immigrants, individuals aged less than 20 (OR = 0.31 p-value < 0.001) and individuals aged 20 to 59 (OR = 0.63, p-value < 0.001) vs. older individuals. Similarly, the cause of death was less often available for non-white individuals (OR = 0.42, p-value <0.001), first-generation immigrants and (OR = 0.71, p-value = 0.009), second-generation immigrants (OR = 0.49, p-value < 0.001), individuals aged less than 20 (OR = 0.028 p-value < 0.001), and individuals aged 20 to 59 (OR = 0.26, p-value < 0.001). These results identified ascertainment bias that is important to consider in analyses that investigate occupational, para-occupational and environmental asbestos exposure as risk factors for mortality in this historic cohort. While this study attempts to describe methods for assessing itemized asbestos exposure profiles for a community in 1930 using Ancestry.com and other publicly accessible databases, it also highlights how historic cohort studies likely underestimate the impact of asbestos exposure on vulnerable populations. Future work will aim to assess mortality patterns in this cohort.

Asbestos in High-Risk Communities: Public Health Implications.

Asbestos-related diseases (ARDs)-mesothelioma, lung cancer, and asbestosis-are well known as occupational diseases. As industrial asbestos use is eliminated, ARDs within the general community from para-occupational, environmental, and natural exposures are more prominent. ARD clusters have been studied in communities including Broni, Italy; Libby, Montana; Wittenoom, Western Australia; Karain, Turkey; Ambler, Pennsylvania; and elsewhere. Community ARDs pose specific public health issues and challenges. Community exposure results in higher proportions of mesothelioma in women and a younger age distribution than occupational exposures. Exposure amount, age at exposure, fiber type, and genetic predisposition influence ARD expression; vulnerable groups include those with social and behavioral risk, exposure to extreme events, and genetic predispositions. To address community exposure, regulations should address all carcinogenic elongated mineral fibers. Banning asbestos mining, use, and importation will not reduce risks from asbestos already in place. Residents of high-risk communities are characteristically exposed through several pathways differing among communities. Administrative responsibility for controlling environmental exposures is more diffuse than for workplaces, complicated by diverse community attitudes to risk and prevention and legal complexity. The National Mesothelioma Registries help track the identification of communities at risk. High-risk communities need enhanced services for screening, diagnosis, treatment, and social and psychological support, including for retired asbestos workers. Legal settlements could help fund community programs. A focus on prevention, public health programs, particularization to specific community needs, and participation is recommended.

Challenging Global Waste Management - Bioremediation to Detoxify Asbestos.

As the 21st century uncovers ever-increasing volumes of asbestos and asbestos-contaminated waste, we need a new way to stop 'grandfather's problem' from becoming that of our future generations. The production of inexpensive, mechanically strong, heat resistant building materials containing asbestos has inevitably led to its use in many public and residential buildings globally. It is therefore not surprising that since the asbestos boom in the 1970s, some 30 years later, the true extent of this hidden danger was exposed. Yet, this severely toxic material continues to be produced and used in some countries, and in others the disposal options for historic uses - generally landfill - are at best unwieldy and at worst insecure. We illustrate the global scale of the asbestos problem via three case studies which describe various removal and/or end disposal issues. These case studies from both industrialised and island nations demonstrate the potential for the generation of massive amounts of asbestos contaminated soil. In each case, the final outcome of the project was influenced by factors such as cost and land availability, both increasing issues, worldwide. The reduction in the generation of asbestos containing materials will not absolve us from the necessity of handling and disposal of contaminated land. Waste treatment which relies on physico-chemical processes is expensive and does not contribute to a circular model economy ideal. Although asbestos is a mineral substance, there are naturally occurring biological-mediated processes capable of degradation (such as bioweathering). Therefore, low energy options, such as bioremediation, for the treatment for asbestos contaminated soils are worth exploring. We outline evidence pointing to the ability of microbe and plant communities to remove from asbestos the iron that contributes to its carcinogenicity. Finally, we describe the potential for a novel concept of creating ecosystems over asbestos landfills ('activated landfills') that utilize nature's chelating ability to degrade this toxic product effectively.

Association between mesothelioma and non-occupational asbestos exposure: systematic review and meta-analysis.

BACKGROUND: The risk of mesothelioma has been shown to be associated with exposure to asbestos fibers. Most of the existing literature focuses on occupational exposure; however, non-occupational asbestos exposure has also been identified as an important risk factor. OBJECTIVE: To estimate the association between mesothelioma and non-occupational asbestos exposure, and evaluate control recruitment and exposure measurement methods. METHODS: A systematic literature review was conducted to identify case-control (CC) and cohort studies that examined the association between mesothelioma and non-occupational exposure to asbestos, including neighborhood, domestic, and household exposure. Meta-analysis was performed to estimate a summary relative risk estimate (SRRE) and 95% confidence interval using random-effects models. Subgroup analyses were also conducted by exposure type, gender, region, and fiber type. RESULTS: Twenty CC and 7 cohort studies were selected. Controls in CC studies were selected from the general population (55%), hospital records (18%), cancer registry (23%) and a combination of population and hospital records (5%). Multiple methods were used to measure neighborhood exposure (e.g., linear distance and direction of residence from an asbestos factory), domestic (e.g., whether living with an asbestos worker) and household exposure (e.g., whether involved in asbestos-containing home improvement projects). Primary meta-analyses suggested a SRRE of mesothelioma of 5.33 (95%CI: 2.53, 11.23) from neighborhood exposure, 4.31 (95%CI, 2.58, 7.20) from domestic exposure, and 2.41 (95%CI, 1.30, 4.48) from household exposure with large I2 statistics ranging from 83-99%. CONCLUSIONS: Non-occupational asbestos exposure is significantly associated with an elevated risk of mesothelioma. Funnel plots indicated a potential of publication bias. Some SRREs should be interpreted with cautions because of high between-studies heterogeneity.

Fitness-for-Duty Assessments of Industrial Firefighters: Guidance for Occupational Medicine Physicians.

: Industrial firefighters share many characteristics with municipal firefighters; however, employers frequently have not addressed or characterized the unique job duties, hazards, and specific physical/mental demands associated with industrial firefighting. In addition, gaps exist in the medical literature with regard to industrial firefighter demographics, behavioral risk factors, and chronic diseases. Finally, the proper methodologies for fitness-for-duty assessment of employees acting in this capacity are lacking. To address these gaps, the American College of Occupational and Environmental Medicine (ACOEM) convened a Task Force in 2014, to develop fitness-for-duty guidance for industrial firefighters. This document highlights these gaps and suggests research opportunities to enhance the health and safety of this population. While an extensive literature review found a lack of studies for this population-thus excluding the development of an evidence-based document-sufficient materials were available from which to draw preliminary conclusions, considerations for best practices, and recommendations for future studies.

Characteristics and Outcomes of an Innovative Train-in-Place Residency Program.

BACKGROUND: Physicians who make a midcareer specialty change may find their options for formal training are limited. Here, we describe a train-in-place program, with measureable outcomes, created to train midcareer physicians who desire formal training in occupational medicine. OBJECTIVE: We evaluated educational outcomes from a novel residency program for midcareer physicians seeking formal training and board certification in occupational medicine. METHODS: Physicians train in place at selected clinical training sites where they practice, and participate in 18 visits to the primary training site over a 2-year period. Program components include competency-based training structured around rotations, mentored projects, and periodic auditing visits to train-in-site locations by program faculty. Main outcome measures are achievement of Accreditation Council for Graduate Medical Education Occupational Medicine Milestones, American College of Occupational and Environmental Medicine competencies, performance on the American College of Preventive Medicine examinations, diversity in selection, placement of graduates, and the number of graduates who remain in the field. RESULTS: Since inception of this program in 1997, there have been 109 graduates who comprise 7.2% of new American Board of Preventive Medicine diplomates over the past decade. Graduates scored competitively on the certifying examination, achieved all milestones, expressed satisfaction with training, and are geographically dispersed, representing every US region. Most practice outside the 25 largest standard metropolitan statistical areas. More than 95% have remained in the field. CONCLUSIONS: Training in place is an effective approach to provide midcareer physicians seeking comprehensive skills and board certification in occupational medicine formal training, and may be adaptable to other specialties.

Realities of environmental toxicity and their ramifications for community engagement.

Research on community responses to environmental toxicity has richly described the struggles of citizens to identify unrecognized toxins, collect their own environmental health facts, and use them to lobby authorities for recognition and remediation. Much of this literature is based on an empiricist premise: it is concerned with exploring differences in how laypeople and experts perceive what is presumed to be a singular toxic reality that preexists these varying perspectives. Here, we seek to reexamine this topic by shifting the focus from facts to facticity-that is, by exploring the many types of knowledge that communities develop about toxicity and how these knowledges articulate with the ideas of scientific and governmental authorities about what kinds of information are valid bases for policymaking. In making this shift, we are influenced by work in semiotic anthropology and science and technology studies (STS), which emphasizes that lived experience generates distinct realities rather than different perceptions of the same underlying state. Using this framework, we present an analysis of oral history interviews conducted in 2013-14 in the small American town of Ambler, Pennsylvania. Part of Ambler's legacy as a nineteenth- and twentieth-century center of asbestos manufacture is that it is home to two massive asbestos-containing waste sites, one of which was being remediated by the Environmental Protection Agency (EPA) at the time of this study. Our interviews demonstrate that even asbestos, a toxin with a well-established public narrative, is a fundamentally different object for different members of the Ambler community. For many of these individuals, the epistemology and practices of the EPA are incongruent with or tangential to their toxicity-related experiences and their consequent concerns for the future. As such, our findings suggest caution in framing the community engagement efforts of environmental health agencies primarily as facilitations of citizen science; this approach does not acknowledge the multiplicity of toxic realities.

Community First Communication: Reversing Information Disparities to Achieve Environmental Justice.

We address how information developed and effectively communicated through community based participatory research (CBPR) can reverse long-standing information disparities, empower a community, and be an agent for sustained change. Substantial information and power disparities existed between the polluted community and both the pollution industry and governmental regulators. An environmental justice partnership between a local community organization, physicians, and university performed CBPR and then developed a novel communication strategy to address a series of information disparities around a local water pollution issue. The community established a set of principles to govern the communication of results as soon as they were determined to be scientifically valid, including informing study participants and the community before other interested parties. CBPR results combined with a community-first communication strategy reversed the preexisting information disparities. The novel communication flow reversed the preferential information flow to industry and government associated with the usual scientific publication process. The community was empowered, and industry and government agencies responded positively to study recommendations. The CBPR results together with community first communication led to adoption of both community-wide and individual solutions and provided powerful motivation for behavioral change by industry and residents.

Congenital anomalies, labor/delivery complications, maternal risk factors and their relationship with perfluorooctanoic acid (PFOA)-contaminated public drinking water.

BACKGROUND: We have previously examined the associations between perfluorooctanoic acid (PFOA) exposure, birth weight and gestational age in individuals exposed to PFOA-contaminated residential drinking water from the Little Hocking Water Association (LHWA). In this investigation, we expand the scope of our analysis to examine the associations between PFOA, congenital anomalies, labor and delivery complications and maternal risk factors. OBJECTIVES: To compare the likelihood of congenital anomalies, labor and delivery complications and maternal risk factors in neonates and their mothers residing in zip codes with public water service provided completely, partially or not at all by the LHWA. METHODS: Logistic regression analyses were performed on singleton neonatal birth outcome data supplied by the Ohio Department of Health to examine the associations between LHWA water service category and the outcomes of interest. When possible, models were adjusted for maternal age, preterm birth, neonatal sex, race, maternal education, alcohol use, tobacco use and diabetic status. RESULTS: Increased PFOA exposure, as assessed by water service category, was not associated with an overall increase in the likelihood of congenital anomalies or any specific diagnosis (adjusted OR: 1.4, 95% CI: 0.34-3.3). The overall likelihood of labor and delivery complications was significantly lower among mothers with water service provided by the LHWA, as compared to mothers not serviced by the LHWA (adjusted OR: 0.65, 95% CI: 0.46-0.92). A significant increase in the likelihood of anemia (crude OR: 11, 95% CI: 1.8-64) and dysfunctional labor (crude OR: 5.3, 95% CI: 1.2-24) was noted for mothers residing within zip codes serviced by the LHWA, but the number of reported cases was very small. CONCLUSION: At the levels measured in the LHWA, we conclude that PFOA is not associated with increased risk of congenital anomalies, most labor and delivery complications and maternal risk factors. Additional research is required to assess the observed associations between PFOA, anemia and dysfunctional labor.

The relationship between birth weight, gestational age and perfluorooctanoic acid (PFOA)-contaminated public drinking water.

BACKGROUND: Recent studies have examined the associations between perfluorooctanoic acid (PFOA) levels in cord blood and maternal plasma with lowered birth weight and gestational age in humans; however, no study has examined these effects in a population of known high PFOA exposure. Residents drinking PFOA-contaminated water from the Little Hocking Water Association (LHWA) in Washington County, Ohio have serum PFOA levels approximately 80 times those in the general U.S. population. OBJECTIVES: To compare birth weights and gestational ages of neonates born to mothers residing in zip codes with water service provided completely, partially or not at all by the LHWA. METHODS: Multiple logistic and linear regression analyses were performed on singleton neonatal birth weight data supplied by the Ohio Department of Health to examine the associations between LHWA water service category (used as a surrogate for PFOA exposure) with mean birth weight, mean gestational age, the likelihood of low birth weight (<2500 g), and the likelihood of preterm birth (<37 completed weeks of gestation). All models were adjusted for maternal age, gestational age, sex, race and population-level socioeconomic status. RESULTS: The incidence of low birth weight, preterm birth, mean birth weight and mean gestational age of neonates did not significantly differ among water service categories. CONCLUSION: Markedly elevated PFOA exposure, as categorized by water service category, is not associated with increased risk of lowered birth weight or gestational age. This study does not confirm earlier findings of an association between PFOA and lowered birth weight observed at normal population levels.

Occupational medicine residency graduate survey: assessment of training programs and core competencies.

OBJECTIVE: This study provides insight into Occupational Medicine (OM) residency graduates and how residency programs are meeting their education goals. METHODS: A survey of graduates from nine OM residency program was performed to evaluate the effectiveness of OM residency training in the United States and Canada. RESULTS: Eighty percent of the OM residency graduates were currently practicing OM. Three-quarters worked in clinical practice for a mean of 20 hr/wk. Other activities varied and included management, teaching and consulting. Ninety-five percent were satisfied with their OM residency training. The competencies acquired were mostly ranked highly as practice requisites, although preparation in clinical OM might be better emphasized in training. Recent OM residency graduates were more likely to be board-certified in OM than other American College of Occupational and Environmental Medicine physician members (73% vs 41%). CONCLUSIONS: OM residency graduates over the past 10 years were highly satisfied with OM residency training, with the training generally meeting practice needs.

Outcomes from the occupational physicians scholarship fund: private support for physician residency training.

The Occupational Physicians Scholarship Fund (OPSF) was established 20 years ago with the goal of helping to address the critical shortage of qualified physicians entering occupational and environmental medicine (OEM). We examined descriptive and outcome measures to evaluate its success. Information was obtained from members of the original board of directors, the OPSF office, and the American Board of Preventive Medicine (ABPM). Most of the scholars (88%) are diplomats of the ABPM, certified in OEM. Scholars represent 6% of board-certified OEM physicians, score higher on the certifying examination than other examinees, practice in all regions of the United States, and are represented in diverse practice settings. The OPSF has achieved its objectives, producing well-trained physicians who contribute to the growth and vitality of the specialty improving worker health, business productivity, and the environment.

Solvents and the skin.

In this paper, we examine how skin structure affects the ability of solvents to irritate and permeate the skin; the patterns of cutaneous injury caused by solvents; the effects of specific solvents on the skin; and the potential for systemic toxicity from dermal absorption.

Workers' compensation and health and productivity.

This article presents a conceptual framework that allows the practitioner to appreciate the relationship between health status and health interventions and productivity in relation to workers' compensation care. Factors important to productivity for individual workers are indicated. Some specific applications of health and productivity theory to the area of workers' compensation from the points of view of the injured worker, the employer, the insurer, and the treating physician are described. Finally, alternate ways of looking at these relationships using the concept of the human capital are briefly discussed.

Exposure assessment for study of olfactory function in workers exposed to styrene in the reinforced-plastics industry.

BACKGROUND: This study was undertaken in conjunction with an evaluation of the olfactory function of 52 persons exposed to styrene vapors to provide quantitative styrene exposure histories of each subject for use in the interpretation of the results of olfactory function testing. METHODS: Current and historic exposures were investigated. Historic exposures were reconstructed from employment records and measurements of styrene exposure made in the subject facilities over the last 15 years. Current exposures were estimated for every exposed subject though personal air sampling and through pre- and post-shift measurements of urinary metabolites of styrene. RESULTS: The study population had been employed in the reinforced-plastics industry for an average of 12.2 +/- 7.4 years. Their mean 8-hr time weighted average (TWA) respirator-corrected annual average styrene exposure was 12.6 +/- 10.4 ppm; mean cumulative exposure was 156 +/- 80 ppm-years. The current respirator-corrected 8-hr TWA average exposure was 15.1 +/- 12.0 ppm. The mean post-shift urinary mandelic and phenylglyoxylic acid (PGA) concentrations were 580 +/- 1,300 and 170 +/- 360 mg/g creatinine, respectively and were highly correlated with air concentrations of styrene. CONCLUSIONS: This quantitative exposure evaluation has provided a well-characterized population, with documented exposure histories stable over time and in the range suitable for the purposes of the associated study of olfactory function.

Occupational contact dermatitis II: risk assessment and prognosis.

Contact dermatitis is a common and important condition in the occupational setting. In a companion paper, I describe changes in the incidence of recorded occupational skin disease from 1972 to 1999. Despite substantial improvements in workplace hygiene, the incidence of occupational skin disease remains half of that recorded in 1972. In the companion paper, it is argued that a more sophisticated approach to prevention and management may be required to substantially reduce the burden of occupational skin disease further. In this paper, I address the present state of risk assessment (including components of hazard identification, measuring or estimating dermal exposure, percutaneous absorption, dose-response relationships, and risk characterization) and the poor prognosis of serious occupational contact dermatitis, with a view to potential improvements in practice and outcomes.

Occupational contact dermatitis I: incidence and return to work pressures.

Since the passage of the United States Occupational Safety and Health Act (OSHA) in 1970, there have been extensive changes in United States workplaces that should have served to enhance the prevention of occupational skin disease (OSD). Analysis of skin diseases reported to OSHA (OSHA recordables) shows that the number of OSDs declined steadily from 1974 to 1983 to about half the previous annual incidence. After 1984, there was a modest resurgence peaking in 1994, with a subsequent decline. A similar but somewhat greater decline in the late 1990s has been observed for occupational respiratory diseases, diseases caused by toxic agents and for poisonings. Likely explanations for the trends in OSD are discussed; the initial decline probably reflected an improvement in workplace conditions, the later resurgence and decline may have been attributable to changes in recording behaviors and in worker's compensation. The decline in recorded OSD since 1996 has been fairly uniform in most major industrial sectors but has been less marked in agriculture, forestry, and fishing so that this sector has replaced manufacturing in recording the highest incidence rate. In 1999, the incidence rate of recorded OSD was 0.49 per 1,000 workers, which appears to grossly under report the true incidence. OSD now constitutes about 10% of all occupational disease cases. Currently, there is increasing emphasis in corporate and occupational medicine on reducing costs and maintaining productivity as well as in preventing occupational injuries and diseases. This is shown by the trend for a greater proportion of workers with occupational conditions to return to modified duty positions rather than to be completely off work. Implications of this phenomena for management of OSD are discussed.