Lung cancer in heavy equipment operators and truck drivers with diesel exhaust exposure in the construction industry

Occupational exposure to diesel exhaust and head and neck cancer: a systematic review and meta-analysis of cohort studies

Exposure to diesel exhaust (DE) and other fossil fuels in the workplace can cause several health effects including cancer. We conducted a systematic review and meta-analysis of cohort studies examining the association between occupational DE exposure and the risk of head and neck cancer (HNC), including cancer of the oral cavity, pharynx and larynx. We included cohort studies mentioned in the Monograph of the International Agency for Research on Cancer, 2014, on DE. Forest plots of relative risk (RR) were constructed for HNC overall and its anatomical subtypes. A random-effects model was used to address heterogeneity between studies. Fifteen articles were included after removing duplicates and irrelevant reports. The summary RR for DE exposure was 1.08 [95% confidence interval (CI) = 1.01-1.17, P heterogeneity = <0.001] for HNC overall, 0.98 (95% CI = 0.87-1.11) for oral cavity, 1.05 (95% CI = 0.77-1.43) for pharyngeal, 1.15 (95% CI = 0.96-1.38) for oral cavity and pharyngeal combined, and 1.13 (95% CI = 1.03-1.24) for laryngeal cancer. There were elevated RRs for incidence studies of HNC (RR = 1.13; 95% CI = 1.05-1.22, P = 0.001), European studies (RR = 1.13; 95% CI = 1.05-1.23, P = 0.001), and female studies (RR = 1.77; 95% CI = 1.31-2.39, P = 0.003). Our study suggested an association between occupational DE exposure and the risk of HNC, particularly laryngeal cancer. Although residual confounding cannot be ruled out, our results support the importance of controlling occupational DE exposure.

Occupational exposure to diesel exhausts and liver and pancreatic cancers: a systematic review and meta-analysis

BACKGROUND

Diesel exhaust (DE) is human carcinogen with sufficient evidence only for lung cancer. Systematic evidence on other cancer types is scarce, thus we aimed to systematically review current literature on the association between occupational DE exposure and risk of liver and pancreatic cancers.

METHODS

We performed a systematic literature review to identify cohort studies on occupational DE exposure and risk of cancers other than lung. We computed pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) for liver and pancreatic cancers using DerSimonian and Laird random-effects model.

RESULTS

Fifteen studies reporting results on pancreatic cancer and fourteen on liver cancer were included. We found a weakly increased risk of pancreatic cancer in workers exposed to DE (RR: 1.07, 95% CI: 1.00, 1.14), mainly driven by results on incidence (RR: 1.11, 95% CI: 1.02, 1.22). As for liver cancer, results were suggestive of a positive association (RR: 1.09; 95% CI: 0.99, 1.19), although a significant estimate was present in studies published before 2000 (RR: 1.41; 95% CI: 1.09, 1.82). We found no compelling evidence of publication bias.

CONCLUSIONS

Our findings suggest an association between occupational DE exposure and liver and pancreatic cancer. Further studies with detailed exposure assessment, environmental monitoring data, and appropriate control for confounders are warranted.

Mortality, cancer incidence, and disability among professional drivers in Slovenia

Literature data about all-cause and cause-specific mortality among professional drivers are inconsistent. Most studies report lower all-cause and higher cause-specific mortality. Higher cause-specific mortality is most often the result of malignant and circulatory diseases. The aim of our retrospective cohort study was to get a better insight into the mortality, cancer incidence, and occupational disability of the entire professional driver population in Slovenia (N=8,231) from 1997 to 2016 through standardised mortality ratio (SMR), standardised proportional mortality ratio (SPMR), standardised cancer incidence ratio (SIR), and standardised disability ratio (SDR). Total mortality was significantly lower than that of the general working population (SMR=0.49; 95 % CI=0.44-0.55). When SPMR was calculated, however, the risk of all-cause mortality increased to 1 (SPMR=1.00; 95 % CI=0.89-1.12), of cancer-related mortality to 1.13 (95 % CI=0.94-1.35), and of injury-related mortality to 1.25 (95 % CI=0.97-1.59). Cancer incidence was lower than in the general male working population for all types of cancer (SIR=0.66; 95 % CI=0.59-0.72), lung cancer included (SIR=0.56; 95 % CI=0.41-0.73). Occupational all-cause and cause-specific disability were also lower than in the rest of the working population. Even though all types of cancer and injuries were established among professional drivers in Slovenia, no major risk stand out. However, our findings may have been skewed by the healthy worker effect.

Diesel Engine Exhaust Exposure in the Ontario Civil Infrastructure Construction Industry

OBJECTIVES

Diesel engine exhaust (DEE) is a known lung carcinogen and a common occupational exposure in Canada. The use of diesel-powered equipment in the construction industry is particularly widespread, but little is known about DEE exposures in this work setting. The objective of this study was to determine exposure levels and identify and characterize key determinants of DEE exposure at construction sites in Ontario.

METHODS

Elemental carbon (EC, a surrogate of DEE exposure) measurements were collected at seven civil infrastructure construction worksites and one trades training facility in Ontario using NIOSH method 5040. Full-shift personal air samples were collected using a constant-flow pump and SKC aluminium cyclone with quartz fibre filters in a 37-mm cassette. Exposures were compared with published health-based limits, including the Dutch Expert Committee on Occupational Safety (DECOS) limit (1.03 µg m-3 respirable EC) and the Finnish Institute of Occupational Health (FIOH) recommendation (5 µg m-3 respirable EC). Mixed-effects linear regression was used to identify determinants of EC exposure.

RESULTS

In total, 149 EC samples were collected, ranging from <0.25 to 52.58 µg m-3 with a geometric mean (GM) of 3.71 µg m-3 [geometric standard deviation (GSD) = 3.32]. Overall, 41.6% of samples exceeded the FIOH limit, mostly within underground worksites (93.5%), and 90.6% exceeded the DECOS limit. Underground workers (GM = 13.20 µg m-3, GSD = 1.83) had exposures approximately four times higher than below grade workers (GM = 3.56 µg m-3, GSD = 1.94) and nine times higher than above ground workers (GM = 1.49 µg m-3, GSD = 1.75). Training facility exposures were similar to above ground workers (GM = 1.86 µg m-3, GSD = 4.12); however, exposures were highly variable. Work setting and enclosed cabins were identified as the key determinants of exposure in the final model (adjusted R2 = 0.72, P < 0.001). The highest DEE exposures were observed in underground workplaces and when using unenclosed cabins.

CONCLUSIONS

This study provides data on current DEE exposure in Canadian construction workers. Most exposures were above recommended health-based limits, albeit in other jurisdictions, signifying a need to further reduce DEE levels in construction. These results can inform a hazard reduction strategy including targeted intervention/control measures to reduce DEE exposure and the burden of occupational lung cancer.

Occupational Risk Factors for Prostate Cancer: A Meta-analysis

Prostate cancer is the second most common cancer in men worldwide. There are many occupational factors that have been suggested to cause prostate cancer. Our aim was to evaluate the evidence for causality by a literature review of occupational factors. We searched literature in Medline and SCOPUS from 1966 to June 30, 2015 to identify occupational risk factors for prostate cancer. The following risk factors were selected: farmers/agricultural workers, pesticides - whole group, and separately organophosphate and organochlorine pesticides, carbamates and triazines, cadmium, chromium, cutting fluids, acrylonitrile, rubber manufacturing, whole body vibration, shift work, flight personnel, ionizing radiation, and occupational physical activity. For each factor a literature search was performed and presented as meta-analysis of relative risk and heterogeneity (Q and I2 index). A total of 168 original studies met the inclusion criteria with 90,688 prostate cancer cases. Significantly increased risks were observed for the following occupational exposures: pesticides (metaRR = 1.15, 95% confidence interval [CI] = 1.01-1.32; I2 = 84%), and specifically group of organochlorine pesticides (meta relative risk [metaRR] = 1.08, 95% CI = 1.03-1.14; I2 = 0%), chromium (metaRR = 1.19, 95% CI = 1.07-1.34; I2 = 31%), shift work (metaRR = 1.25, 95% CI = 1.05-1.49; I2 = 78%) and pilots (metaRR = 1.41, 95% CI = 1.02-1.94; I2 = 63%) and occupational physical activity in cohort studies (metaRR = 0.87, 95% CI = 0.81-0.94; I2 = 0%). The literature review supports a causal association for a few of the previously suggested factors.

Occupational health and safety of road haulage company employees

Background:

This paper follows up on a project that was launched in 2008 and contributed to the development of the new Italian Society of Occupational Medicine (SIML) guidelines for the road haulage industry.

Objective:

To reach a better understanding of occupational illness amongst truck drivers, in order to define appropriate health monitoring protocols and promote a healthy life-style.

Methods:

We assessed 673 male drivers (mean age 43.85 years, SD 9.56; mean working seniority 27.28 years, SD 10.59), employed by 46 different companies. The drivers, who were gradually recruited in the study over the years, had a maximum of 8 re-assessments each, for a total of 2608 examinations. We applied a survey protocol consisting in a medical examination, questionnaires for the most common risks and instrumental and laboratory tests in compliance with SIML guidelines.

Results:

We identified a total of 44 work-related diseases: 22 cases of noise-induced hearing loss (NIHL) and 22 cases of lumbar degenerative disc disease. As regards metabolic disorders, we observed 28 cases of diabetes mellitus, in most cases (71.4%) as a first diagnosis or under poor therapeutic control. We observed poorly-controlled hypertension in 103 drivers, the majority of whom (54%) were diagnosed for the first time. Over 30% of the workers in our study were obese and approximately 40% were tobacco smokers. We identified just 9 individuals (1.3%) with a positive toxicological screening for use of recreational drugs. Our data confirm a high prevalence of occupational illness amongst truck drivers. Cardiovascular and metabolic conditions require close monitoring.

Contact dermatitis is an unrecognized problem in the construction industry: Comparison of four different assessment methods

BACKGROUND

A high contact dermatitis symptoms prevalence has been observed in Dutch construction workers.

METHODS

Contact dermatitis was diagnosed by an expert panel using questionnaire data and photographs of 751 subjects' hands. A subset was evaluated by two occupational physicians. Their diagnoses were compared to those of the expert panel. In addition, two self-reported questionnaire-based assessment methods were compared to the expert panel evaluation. Associations between contact dermatitis and determinants were assessed using log-binomial regression analysis.

RESULTS

Contact dermatitis prevalence was high: 61.4% (expert panel's diagnosis) and 32.9% (self-reported). Agreement between occupational physicians and the expert panel was low but increased after training. Washing hands with solvents and performing job-related tasks at home were related to contact dermatitis.

CONCLUSIONS

Contact dermatitis prevalence among construction workers is high. Recognition of contact dermatitis by occupational physicians is poor but can be improved by training. Awareness of skin disorders should be raised.

A critical review of the relationship between occupational exposure to diesel emissions and lung cancer risk

In 2012, a working group of the International Agency for Research on Cancer classified diesel exhaust (DE) as a human carcinogen (Group 1). This decision was primarily based on the findings of the Diesel Exhaust in Miners Study (DEMS). The disparity between the results of various methodological approaches applied to the DEMS led to several critical commentaries. An expert panel was subsequently set up by the Health Effects Institute to evaluate the DEMS results, together with a large study in the trucking industry. The panel concluded that both studies provided a useful basis for quantitative risk assessments (QRAs) of DE exposure. However, the results of both studies were non-definitive as the studies suffer from several methodological shortcomings. We conducted a critical review of the studies used by the International Agency for Research on Cancer (IARC) working group to evaluate the relationship between DE and lung cancer. The aim was to assess whether the available studies support the statement of a causal relationship and, secondarily if they could be used for QRA. Our review highlights several methodological flaws in the studies, amongst them overadjustment bias, selection bias, and confounding bias. The conclusion from our review is that the currently published studies provide little evidence for a definite causal link between DE exposure and lung cancer risk. Based on two studies in miners, the DEMS and the German Potash Miners study, QRA may be conducted. However, the DEMS data should be reanalyzed in advance to avoid bias that affects the presently published risk estimates.

Work environment and safety climate in the Swedish merchant fleet

Purpose

To get knowledge of the work environment for seafarers sailing under the Swedish flag, in terms of safety climate, ergonomical, chemical and psychosocial exposures, and the seafarers self-rated health and work ability.

Methods

A Web-based questionnaire was sent to all seafarers with a personal e-mail address in the Swedish Maritime Registry (N = 5608). Comparisons were made mainly within the study population, using Student’s t test, prevalence odds ratios and logistic regressions with 95% confidence intervals.

Results

The response rate was 35% (N = 1972; 10% women, 90% men), with 61% of the respondents working on deck, 31% in the engine room and 7% in the catering/service department (1% not classifiable). Strain on neck, arm or back and heavy lifting were associated with female gender (p = 0.0001) and younger age (below or above 30 years of age, p < 0.0001). Exposures to exhausts, oils and dust were commonly reported. Major work problems were noise, risk of an accident and vibrations from the hull of the ship. The safety climate was high in comparison with that in land-based occupations. One-fourth had experienced personal harassment or bullying during last year of service.

Conclusions

Noise, risk of accidents, hand/arm and whole-body vibrations and psychosocial factors such as harassment were commonly reported work environment problems among seafarers within the Swedish merchant fleet.

Electronic supplementary material

The online version of this article (doi:10.1007/s00420-016-1180-0) contains supplementary material, which is available to authorized users.

Occupation, industry, and the risk of prostate cancer: a case-control study in Montréal, Canada

BACKGROUND

Age, family history and ancestry are the only recognized risk factors for prostate cancer (PCa) but a role for environmental factors is suspected. Due to the lack of knowledge on the etiological factors for PCa, studies that are both hypothesis-generating and confirmatory are still needed. This study explores relationships between employment, by occupation and industry, and PCa risk.

METHODS

Cases were 1937 men aged ≤75 years with incident PCa diagnosed across Montreal French hospitals in 2005-2009. Controls were 1994 men recruited concurrently from electoral lists of French-speaking Montreal residents, frequency-matched to cases by age. In-person interviews elicited occupational histories. Unconditional logistic regression estimated odds ratios (OR) and 95 % confidence intervals (CI) for the association between employment across 696 occupations and 613 industries and PCa risk, adjusting for potential confounders. Multinomial logistic models assessed risks by PCa grade. Semi-Bayes (SB) adjustment accounted for the large number of associations evaluated.

RESULTS

Consistently positive associations-and generally robust to SB adjustment-were found for occupations in forestry and logging (OR 1.9, 95 % CI: 1.2-3.0), social sciences (OR 1.6, 95 % CI: 1.1-2.2) and for police officers and detectives (OR: 1.8, 95 % CI 1.1-2.9). Occupations where elevated risk of high grade PCa was found included gasoline station attendants (OR 4.3, 95 % CI 1.8-10.4) and textile processing occupations (OR 1.8, 95 % CI 1.1-3.2). Aside from logging, industries with elevated PCa risk included provincial government and financial institutions. Occupations with reduced risk included farmers (OR 0.6, 95 % CI 0.4-1.0) and aircraft maintenance workers (OR 0.1, 95 % CI 0.0-0.7).

CONCLUSIONS

Excess PCa risks were observed across several occupations, including predominantly white collar workers. Further analyses will focus on specific occupational exposures.

Relationships between chronic obstructive pulmonary disease and lung cancer: biological insights

Lung cancer (LC) has become one of the leading causes of preventable death in the last few decades. Cigarette smoking (CS) stays as the main etiologic factor of LC despite that many other causes such as occupational exposures, air pollution, asbestos, or radiation have also been implicated. Patients with chronic obstructive pulmonary disease (COPD), which also represents a major cause of morbidity and mortality in developed countries, exhibit a significantly greater risk of LC. The study of the underlying biological mechanisms that may predispose patients with chronic respiratory diseases to a higher incidence of LC has also gained much attention in the last few years. The present review has been divided into three major sections in which different aspects have been addressed: (I) relevant etiologic agents of LC; (II) studies confirming the hypothesis that COPD patients are exposed to a greater risk of developing LC; and (III) evidence on the most relevant underlying biological mechanisms that support the links between COPD and LC. Several carcinogenic agents have been described in the last decades but CS remains to be the leading etiologic agent in most geographical regions in which the incidence of LC is very high. Growing evidence has put the line forward the implications of COPD and especially of emphysema in LC development. Hence, COPD represents a major risk factor of LC in patients. Different avenues of research have demonstrated the presence of relevant biological mechanisms that may predispose COPD patients to develop LC. Importantly, the so far identified biological mechanisms offer targets for the design of specific therapeutic strategies that will further the current treatment options for patients with LC. Prospective screening studies, in which patients with COPD should be followed up for several years will help identify biomarkers that may predict the risk of LC among these patients.

Particulate matter properties and health effects: consistency of epidemiological and toxicological studies

Identifying the ambient particulate matter (PM) fractions or constituents, critically involved in eliciting adverse health effects, is crucial to the implementation of more cost-efficient abatement strategies to improve air quality. This review focuses on the importance of different particle properties for PM-induced effects, and whether there is consistency in the results from epidemiological and experimental studies. An evident problem for such comparisons is that epidemiological and experimental data on the effects of specific components of ambient PM are limited. Despite this, some conclusions can be drawn. With respect to the importance of the PM size-fractions, experimental and epidemiological studies are somewhat conflicting, but there seems to be a certain consistency in that the coarse fraction (PM10-2.5) has an effect that should not be neglected. Better exposure characterization may improve the consistency between the results from experimental and epidemiological studies, in particular for ultrafine particles. Experimental data indicate that surface area is an important metric, but composition may play an even greater role in eliciting effects. The consistency between epidemiological and experimental findings for specific PM-components appears most convincing for metals, which seem to be important for the development of both pulmonary and cardiovascular disease. Metals may also be involved in PM-induced allergic sensitization, but the epidemiological evidence for this is scarce. Soluble organic compounds appear to be implicated in PM-induced allergy and cancer, but the data from epidemiological studies are insufficient for any conclusions. The present review suggests that there may be a need for improvements in research designs. In particular, there is a need for better exposure assessments in epidemiological investigations, whereas experimental data would benefit from an improved comparability of studies. Combined experimental and epidemiological investigations may also help answer some of the unresolved issues.

National Survey of US Long-Haul Truck Driver Health and Injury: health behaviors

OBJECTIVE

To compare selected health behaviors and body mass index (modifiable risk factors) of US long-haul truck drivers to the US working population by sex.

METHODS

The National Survey of US Long-Haul Truck Driver Health and Injury interviewed a nationally representative sample of long-haul truck drivers (n = 1265) at truck stops. Age-adjusted results were compared with national health surveys.

RESULTS

Compared with US workers, drivers had significantly higher body mass index, current cigarette use, and pack-years of smoking; lower prevalence of annual influenza vaccination; and generally lower alcohol consumption. Physical activity level was low for most drivers, and 25% had never had their cholesterol levels tested.

CONCLUSIONS

Working conditions common to long-haul trucking may create significant barriers to certain healthy behaviors; thus, transportation and health professionals should address the unique work environment when developing interventions for long-haul drivers.

Traffic-related air pollution and lung cancer: A meta-analysis

Background

We conducted a meta-analysis to evaluate the association between traffic-related air pollution and lung cancer in order to provide evidence for control of traffic-related air pollution.

Methods

Several databases were searched for relevant studies up to December 2013. The quality of articles obtained was evaluated by the Strengthening the Reporting of Observational Studies in Epidemiology checklist. Statistical analysis, including pooling effective sizes and confidential intervals, was performed.

Results

A total of 1106 records were obtained through the database and 36 studies were included in our analysis. Among the studies included, 14 evaluated the association between ambient exposure to traffic-related air pollution and lung cancer and 22 studies involved occupational exposure to air pollution among professional drivers. Twenty-two studies were marked A level regarding quality, 13 were B level, and one was C level. Exposure to nitrogen dioxide (meta-odds ratio [OR]: 1.06, 95% confidence interval [CI]: 0.99–1.13), nitrogen oxide (meta-OR: 1.04, 95% CI: 1.01–1.07), sulfur dioxide (meta-OR: 1.03, 95% CI: 1.02–1.05), and fine particulate matter (meta-OR: 1.11, 95% CI: 1.00–1.22) were positively associated with a risk of lung cancer. Occupational exposure to air pollution among professional drivers significantly increased the incidence (meta-OR: 1.27, 95% CI: 1.19–1.36) and mortality of lung cancer (meta-OR: 1.14, 95% CI: 1.04–1.26).

Conclusion

Exposure to traffic-related air pollution significantly increased the risk of lung cancer.

Investing in prospective cohorts for etiologic study of occupational exposures

Prospective cohorts have played a major role in understanding the contribution of diet, physical activity, medical conditions, and genes to the development of many diseases, but have not been widely used for occupational exposures. Studies in agriculture are an exception. We draw upon our experience using this design to study agricultural workers to identify conditions that might foster use of prospective cohorts to study other occupational settings. Prospective cohort studies are perceived by many as the strongest epidemiologic design. It allows updating of information on exposure and other factors, collection of biologic samples before disease diagnosis for biomarker studies, assessment of effect modification by genes, lifestyle, and other occupational exposures, and evaluation of a wide range of health outcomes. Increased use of prospective cohorts would be beneficial in identifying hazardous exposures in the workplace. Occupational epidemiologists should seek opportunities to initiate prospective cohorts to investigate high priority, occupational exposures.

Profiling contextual factors which influence safety in heavy vehicle industries

A significant proportion of worker fatalities within Australia result from truck-related incidents. Truck drivers face a number of health and safety concerns. Safety culture, viewed here as the beliefs, attitudes and values shared by an organisation's workers, which interact with their surrounding context to influence behaviour, may provide a valuable lens for exploring safety-related behaviours in heavy vehicle operations. To date no major research has examined safety culture within heavy vehicle industries. As safety culture provides a means to interpret experiences and generate behaviour, safety culture research should be conducted with an awareness of the context surrounding safety. The current research sought to examine previous health and safety research regarding heavy vehicle operations to profile contextual factors which influence health and safety. A review of 104 peer-reviewed papers was conducted. Findings of these papers were then thematically analysed. A number of behaviours and scenarios linked with crashes and non-crash injuries were identified, along with a selection of health outcomes. Contextual factors which were found to influence these outcomes were explored. These factors were found to originate from government departments, transport organisations, customers and the road and work environment. The identified factors may provide points of interaction, whereby culture may influence health and safety outcomes.

Prostate cancer and occupational exposure to whole-body vibration in a national population-based cohort study

BACKGROUND

Following preliminary evidence from observational studies, we test the potential relationship between whole-body vibration (WBV) and prostate cancer in a cohort study.

METHODS

WBV exposure was assigned based on occupation in 1991 and 1,107,700 participants were followed for incident prostate cancer until the end of 2003. Adjusted hazard rate ratios (HRs) were calculated using Cox proportional hazards modeling.

RESULTS

17,922 incident prostate cancer cases were observed. WBV-exposed men in Natural and Applied Sciences Occupations had a 37% elevated risk of prostate cancer (95% CI 1.09-1.72) and WBV-exposed men in Trades, Transport, and Equipment Operators Occupations had a 9% reduced risk (95% CI 0.86-0.97). Independent of WBV exposure, small but significant differences in risk were seen for several occupational categories.

CONCLUSIONS

We found no consistent relationship between WBV and prostate cancer. Further research could focus on other exposures or specific occupations in the studied categories to determine what may be contributing to the observed differences in prostate cancer risk.

Diesel exhaust exposure and the risk of lung cancer--a review of the epidemiological evidence

To critically evaluate the association between diesel exhaust (DE) exposure and the risk of lung cancer, we conducted a systematic review of published epidemiological evidences. To comprehensively identify original studies on the association between DE exposure and the risk of lung cancer, literature searches were performed in literature databases for the period between 1970 and 2013, including bibliographies and cross-referencing. In total, 42 cohort studies and 32 case-control studies were identified in which the association between DE exposures and lung cancer was examined. In general, previous studies suffer from a series of methodological limitations, including design, exposure assessment methods and statistical analysis used. A lack of objective exposure information appears to be the main problem in interpreting epidemiological evidence. To facilitate the interpretation and comparison of previous studies, a job-exposure matrix (JEM) of DE exposures was created based on around 4,000 historical industrial measurements. The values from the JEM were considered during interpretation and comparison of previous studies. Overall, neither cohort nor case-control studies indicate a clear exposure-response relationship between DE exposure and lung cancer. Epidemiological studies published to date do not allow a valid quantification of the association between DE and lung cancer.

Validation of the Health-Promoting Lifestyle Profile II for Hispanic male truck drivers in the Southwest

The aims of the study were to validate the English and Spanish Versions of the Health-Promoting Lifestyle Profile II (HPLP II) with Hispanic male truck drivers and to determine if there were any differences in drivers' responses based on driving responsibility. The methods included a descriptive correlation design, the HPLP II (English and Spanish versions), and a demographic questionnaire. Fifty-two Hispanic drivers participated in the study. There were no significant differences in long haul and short haul drivers' responses to the HPLP II. Cronbach's alpha for the Spanish version was .97 and the subscales alphas ranged from .74 to .94. The English version alpha was .92 and the subscales ranged from .68 to .84. Findings suggest the subscales of Health Responsibility, Physical Activities, Nutrition, and Spirituality Growth on the HPLP II Spanish and English versions may not adequately assess health-promoting behaviors and cultural influences for the Hispanic male population in the southwestern border region.

Mortality and cancer incidence in a copper-zinc cohort

Previous studies of copper-zinc workers have primarily observed significant increases in lung and other respiratory cancers. This study concurrently examined cancer incidence and cause-specific mortality for a cohort of workers at a copper-zinc producer in Ontario, Canada, from 1964 to 2005. Significant elevations in lung cancer incidence were observed for males in the overall cohort (standardized incidence ratio [SIR] = 124, 95% confidence interval [CI] = 102-150) and for surface mine (SIR = 272, 95% CI = 124-517), concentrator (SIR = 191, 95% CI = 102-327), and central maintenance (SIR = 214, 95% CI = 125-343) employees. Significant elevations of non-Hodgkin's lymphoma incidence were observed for male underground mine employees (SIR = 232, 95% CI = 111-426). Occupational etiology cannot be ascertained with the current exploratory study design. Future studies could (1) incorporate exposure assessment for subgroups within the existing cohort and (2) determine the efficacy of wellness programs in partnership with the local health unit.

Health effects research and regulation of diesel exhaust: an historical overview focused on lung cancer risk

The mutagenicity of organic solvent extracts from diesel exhaust particulate (DEP), first noted more than 55 years ago, initiated an avalanche of diesel exhaust (DE) health effects research that now totals more than 6000 published studies. Despite an extensive body of results, scientific debate continues regarding the nature of the lung cancer risk posed by inhalation of occupational and environmental DE, with much of the debate focused on DEP. Decades of scientific scrutiny and increasingly stringent regulation have resulted in major advances in diesel engine technologies. The changed particulate matter (PM) emissions in "New Technology Diesel Exhaust (NTDE)" from today's modern low-emission, advanced-technology on-road heavy-duty diesel engines now resemble the PM emissions in contemporary gasoline engine exhaust (GEE) and compressed natural gas engine exhaust more than those in the "traditional diesel exhaust" (TDE) characteristic of older diesel engines. Even with the continued publication of epidemiologic analyses of TDE-exposed populations, this database remains characterized by findings of small increased lung cancer risks and inconsistent evidence of exposure-response trends, both within occupational cohorts and across occupational groups considered to have markedly different exposures (e.g. truckers versus railroad shopworkers versus underground miners). The recently published National Institute for Occupational Safety and Health (NIOSH)-National Cancer Institute (NCI) epidemiologic studies of miners provide some of the strongest findings to date regarding a DE-lung cancer association, but some inconsistent exposure-response findings and possible effects of bias and exposure misclassification raise questions regarding their interpretation. Laboratory animal studies are negative for lung tumors in all species, except for rats under lifetime TDE-exposure conditions with durations and concentrations that lead to "lung overload." The species specificity of the rat lung response to overload, and its occurrence with other particle types, is now well-understood. It is thus generally accepted that the rat bioassay for inhaled particles under conditions of lung overload is not predictive of human lung cancer hazard. Overall, despite an abundance of epidemiologic and experimental data, there remain questions as to whether TDE exposure causes increased lung cancers in humans. An abundance of emissions characterization data, as well as preliminary toxicological data, support NTDE as being toxicologically distinct from TDE. Currently, neither epidemiologic data nor animal bioassay data yet exist that directly bear on NTDE carcinogenic potential. A chronic bioassay of NTDE currently in progress will provide data on whether NTDE poses a carcinogenic hazard, but based on the significant reductions in PM mass emissions and the major changes in PM composition, it has been hypothesized that NTDE has a low carcinogenic potential. When the International Agency for Research on Cancer (IARC) reevaluates DE (along with GEE and nitroarenes) in June 2012, it will be the first authoritative body to assess DE carcinogenic health hazards since the emergence of NTDE and the accumulation of data differentiating NTDE from TDE.

Mortality and cancer incidence in a copper-zinc cohort

Previous studies of copper-zinc workers have primarily observed significant increases in lung and other respiratory cancers. This study concurrently examined cancer incidence and cause-specific mortality for a cohort of workers at a copper-zinc producer in Ontario, Canada, from 1964 to 2005. Significant elevations in lung cancer incidence were observed for males in the overall cohort (standardized incidence ratio [SIR] = 124, 95% confidence interval [CI] = 102-150) and for surface mine (SIR = 272, 95% CI = 124-517), concentrator (SIR = 191, 95% CI = 102-327), and central maintenance (SIR = 214, 95% CI = 125-343) employees. Significant elevations of non-Hodgkin's lymphoma incidence were observed for male underground mine employees (SIR = 232, 95% CI = 111-426). Occupational etiology cannot be ascertained with the current exploratory study design. Future studies could (1) incorporate exposure assessment for subgroups within the existing cohort and (2) determine the efficacy of wellness programs in partnership with the local health unit.

Mortality among Members of a Truck Driver Trade Association

Previous studies report that truck drivers are at increased risk for illness and on-the-job mortality. It is unknown whether owner-operator truck drivers face the same risks as employee drivers, yet few studies have targeted owner-operators as a study population. This study examined the overall and cause-specific mortality ratios for a cohort with owner-operator truck drivers constituting 69% of the study population. Of the 26 major disease classifications and 92 specific causes of death examined, only mortality due to transportation accidents was significantly elevated (standardized mortality ratio = 1.52, 95% confidence interval = 1.36–1.70). Leading causes of death were ischemic heart disease and lung cancer, although risk was below that of the general population. Transportation accidents pose a particular hazard for members of the trade association. The absence of excess disease mortality deserves careful interpretation, and may be due to both a strong healthy worker effect and a short monitoring period.

Worksite-induced morbidities among truck drivers in the United States

A critical review was conducted of social, psychological, and health science literature on the array of health risks and morbidities of truckers. Multilevel worksite-induced strains (e.g., long work hours and fatigue, shift work and sleep deprivation, postural fatigue and exposure to noise and vibration, sedentary lifestyle and unhealthy diet, exposure to diesel exhaust fumes, and other occupational stressors) were categorized into six primary morbidities for truckers: (1) psychological and psychiatric disorders; (2) detriments resulting from disrupted biological cycles; (3) musculoskeletal disorders; (4) cancer and respiratory morbidities; (5) cardiovascular disease; and (6) risk-laden substance use and sexual practices. Elevated morbidity risks suggest the need for the design and implementation of systematic epidemiological research and environmental interventions in the transport sector.

Worksite-Induced Morbidities among Truck Drivers in the United States

A critical review was conducted of social, psychological, and health science literature on the array of health risks and morbidities of truckers. Multilevel worksite-induced strains (e.g., long work hours and fatigue, shift work and sleep deprivation, postural fatigue and exposure to noise and vibration, sedentary lifestyle and unhealthy diet, exposure to diesel exhaust fumes, and other occupational stressors) were categorized into six primary morbidities for truckers: (1) psychological and psychiatric disorders; (2) detriments resulting from disrupted biological cycles; (3) musculoskeletal disorders; (4) cancer and respiratory morbidities; (5) cardiovascular disease; and (6) risk-laden substance use and sexual practices. Elevated morbidity risks suggest the need for the design and implementation of systematic epidemiological research and environmental interventions in the transport sector.

Lung cancer and diesel exhaust: a critical review of the occupational epidemiology literature

The diesel exhaust (DE)-lung cancer hypothesis is evaluated. Diesel power became common after World War II, exposure was to traditional diesel exhaust (TDE) before 1988. In the next, 20 years, emissions were modified to new-technology diesel exhaust (NTDE) containing 1% of pre-1988 levels of diesel particulate matter (DPM). Nearly all pre-1990 studies were cohorts with primarily pre-diesel exposures. This review focuses on the proportion of cases with >20 years since initial DE exposure; strength of association; biological gradients; roles of chance, bias, and confounding; and consistency in 13 diesel studies. Five studies had adequate latency, six had a minority of workers with >20 years' latency, and in two studies most workers had inadequate latency. This pattern suggests too few relevant studies for evaluating the DE-lung cancer hypothesis. The 16 highest exposure categories showed 7 with probable associations (relative risk [RR] > 1.5), 7 with improbable or no associations (RRs < 1.2), and 2 with possible associations (RRs 1.2-1.5). This random pattern with many weak RRs does not support the DE-lung cancer hypothesis. Ten of 34 exposure-response (E-R) analyses showed positive trends and 24 had indeterminate or negative trends. This small number of positive biological gradients does not support causality. Weight of evidence suggests 70% of studies are indeterminate, whereas 30% are positive or negative, indicating a lack of consistency. To support a traditional diesel exhaust-lung cancer hypothesis requires more studies with longer follow-up and quantitative E-R analyses.

Occupations and lung cancer: a population-based case-control study in British Columbia

An investigation based on a large population-based case-control study in British Columbia, Canada, was conducted to identify high-risk occupations for lung cancer by histological subtypes. Subjects were 14,755 male incident cancer cases for whom lifetime occupational histories and information on smoking and relevant covariates were collected. Occupational associations for 2998 lung cancer cases, including histological subtypes, were assessed by logistic regression using other cancer cases, excluding smoking-related cancers, as controls. An excess risk of lung cancer was found among workers in metal processing, bakers, and ship deck crew for all histological subtypes, and construction workers, chefs and cooks, and medical workers for specific histological subtypes. Occupational associations that are unique to histological subtypes of lung cancer were identified. Owing to a scarcity of literature in this area, future research needs to focus on confirming these histological associations, and identifying the risk from key exposures found within these occupations (e.g., medical radiation, electromagnetic fields, and cooking fumes).

Moderate increases in ambient PM2.5 and ozone are associated with lung function decreases in beach lifeguards

OBJECTIVE

Exposure to pollutants would adversely affect lung function of healthy athletes.

METHODS

Pulmonary function was recorded on beach lifeguards at three different times during the day. Daily and average peak pollutant levels were calculated. Linear regression analyses were made comparing lung function changes in response to pollutant levels. A multivariate model was constructed to explain the combined effects of pollutants.

RESULTS

Afternoon forced vital capacity (FVC) and forced expired volume in 1 second (FEV1) decreased significantly compared with morning values and decreased with increasing fine particulates (PM2.5). FEV1/FVC decreased with increasing ozone (O3) levels.

CONCLUSION

The deleterious effect of PM2.5 and O3 were transient and occurred at pollutant levels far below national standards. At low levels of exposure, PM2.5 was associated with reduced lung volumes, while increasing O3 levels were associated with airway obstruction.

Occupational and indoor air exposure to persistent organic pollutants: a review of passive sampling techniques and needs

Exposure to persistent organic pollutants (POPs) and related compounds such as PCBs, brominated flame retardants, organochlorine pesticides and PAHs is regarded as an important environmental risk factor for humans. Recently concerns about POPs resulted in the international protocol called the Stockholm Convention on POPs. Air quality standards (indoor, outdoor and occupational) for PAHs and other POPs will also be applied in the EU in the future. This will bring requirements for monitoring, to check for compliance and to reduce human exposures to POPs. This can occur from point sources and in various microenvironments, indoors, outdoors and in workplaces. Monitoring can be undertaken either by an active (pumped) method or using a passive (diffusive) air sampling (PAS) device. To date, PAS for POPs have mainly been used as integrating (long-term) samplers for ambient (outdoor) air. However, there are several reasons to develop PAS for monitoring of POPs in occupational and indoor environments. We discuss the potential advantages, limitations and developments needed, so that PAS can be used reliably and routinely indoors and in occupational settings for POPs.

Diesel exhaust and coal mine dust: lung cancer risk in occupational settings

Conflicting evidence on the carcinogenicity of diesel exhaust (DE) and coal mine dust in occupational settings exist. Exposure measurement in most studies is inferred on the basis of job classifications and may lead to misclassification. Confounding behavioral factors (i.e., smoking) and occupational risk factors (exposure to asbestos, arsenic, radon) need to be considered. We evaluated the epidemiological evidence and current findings of the carcinogenicity of DE and coal mine dust in occupational settings. Pertaining literature was identified through Medline search and recent review articles. Strengths and limitations of recent approaches are discussed. Many epidemiological studies have addressed the question of carcinogenicity in workers exposed to DE, and most showed a low-to-medium increase in the risk of bronchial carcinoma. The pooled relative risk (RR) estimates lie between 1.33 and 1.47, and a consistent rise in risk across various job categories and study designs point to a causal relationship. Data on the carcinogenicity of coal mine dust are less consistent and the potential for confounding by unmeasured risk factors (arsenic, radon, DE) are higher. While silica as one of its components has been evaluated as carcinogenic, there is inadequate evidence for the carcinogenicity of pure coal dust according to the International Agency for Research on Cancer (IARC). There is sufficient evidence for a causal relationship between DE and lung cancer in occupational settings. The evidence for coal mine dust is less convincing, but individual studies show an increase in risk of lung cancer in exposed workers.

Carcinogens in the Construction Industry

The construction industry is a complex work environment. The work sites are temporary and rapidly changing. Asbestos has been widely used in construction industry, but the risks were primarily detected in specialized trades, such as insulation workers and plumbers. Today, the majority of cases related to asbestos exposure will occur in other occupational groups in the construction industry. In a large cohort of Swedish construction workers, insulators and plumbers constituted 37% of all cases of pleural mesothelioma between 1975 and 1984 while they constituted 21% of the cases between 1998 and 2002. It is estimated that 25-40% of all male cases of pleural mesothelioma in Sweden are caused by asbestos exposure in the construction trades. There are many other known carcinogens occurring in the construction industry, including PAHs, diesel exhausts, silica, asphalt fumes, solvents, etc., but it is difficult to estimate exposures and thus the size of the risk. The risk of cancer is less easy to detect with traditional epidemiological methods in the construction industry than in other industrial sectors. It is not sufficient to rely upon broad epidemiological data to estimate the risk of cancer due chemicals in the construction industry. Thus, a strategy to decrease exposure, e.g., to dust, seems a feasible way to reduce the risk.

The influence of occupational exposure to pesticides, polycyclic aromatic hydrocarbons, diesel exhaust, metal dust, metal fumes, and mineral oil on prostate cancer: a prospective cohort study

AIMS

To investigate the relation between exposure to pesticides, polycyclic aromatic hydrocarbons (PAHs), diesel exhaust, metal dust, metal fumes, and mineral oil in relation to prostate cancer incidence in a large prospective study.

METHODS

This cohort study was conducted among 58,279 men in the Netherlands. In September 1986, cohort members (55-69 years) completed a self-administered questionnaire on potential cancer risk factors, including job history. Follow up for prostate cancer incidence was established by linkage to cancer registries until December 1995 (9.3 years of follow up). The analyses included 1386 cases of prostate cancer and 2335 subcohort members. A blinded case-by-case expert exposure assessment was carried out to assign cases and subcohort members a cumulative probability of exposure for each potential carcinogenic exposure.

RESULTS

In multivariate analyses there was a significant negative association for pesticides (RR 0.60; 95% CI 0.37 to 0.95) when comparing the highest tertile of exposure to pesticides with no exposure. No association was found for occupational exposure to PAHs (RR 0.75; 95% CI 0.42 to 1.31), diesel exhaust (RR 0.81; 95% CI 0.62 to 1.06), metal dust (RR 1.01; 95% CI 0.72 to 1.40), metal fumes (RR 1.11; 95% CI 0.80 to 1.54), or mineral oil (RR 0.99; 95% CI 0.66 to 1.48) when comparing the highest tertile of exposure with no exposure. In subgroup analysis, with respect to tumour invasiveness and morphology, null results were found for occupational exposure to pesticides, PAH, diesel exhaust, metal dust, metal fumes, and mineral oil.

CONCLUSIONS

These results suggest a negative association between occupational exposure to pesticides and prostate cancer. For other carcinogenic exposures results suggest no association between occupational exposure to PAHs, diesel exhaust, metal dust, metal fumes, or mineral oil and prostate cancer.

Multiple myeloma and diesel and other occupational exposures in swedish construction workers

We examined the relationships between occupational exposures and the risk of multiple myeloma among male construction workers in Sweden. A total of 446 myeloma subjects were identified among 365,424 male workers followed from 1971 to 1999. Occupational exposure was assessed using a semiquantitative job-exposure matrix, based on a survey carried out by the Construction Industry's Organization for Working Environment, Occupational Safety and Health in Sweden. Rate ratios (RRs) in the exposed groups relative to the unexposed groups were estimated by Poisson regression. We found an increased risk (RR = 1.3, 95% CI 1.04-1.71) among construction workers exposed to diesel exhaust. Adjustment for other occupational exposures did not change this estimate (RR = 1.3, 95% CI 1.00-1.77). However, there was no monotonic increase in risk with estimated level of exposure (RR for low = 1.4, moderate = 1.1, high = 1.4). There was no evidence of increased risk associated with the other occupational exposures among these construction workers, including asbestos, asphalt, cement dust, metal dust, mineral wool, organic solvents, stone dust and wood dust. Occupational exposure to diesel exhaust in the Swedish construction industry may present a small risk of multiple myeloma, but lack of an exposure-response trend tempers our ability to draw clear conclusions.