Exposure to fibres and risk of pleural mesothelioma in the Norwegian Offshore Petroleum Workers cohort.

OBJECTIVES: Pleural mesothelioma is a rare respiratory cancer, mainly caused by inhalation of asbestos fibres. Other inorganic fibres are also suggested risk factors. We aimed to investigate the association between exposure to asbestos or refractory ceramic fibres (RCFs) and pleural mesothelioma among male Norwegian offshore petroleum workers. METHODS: Among 25 347 men in the Norwegian Offshore Petroleum Workers (NOPW) cohort (1965-1998), 43 pleural mesothelioma cases were identified through the Cancer Registry of Norway (1999-2022). A case-cohort study was conducted with 2095 randomly drawn non-cases from the cohort. Asbestos and RCF exposures were assessed with expert-made job-exposure matrices (JEMs). Weighted Cox regression was used to estimate HRs and 95% CIs, adjusted for age at baseline and pre-offshore employment with likely asbestos exposure. RESULTS: An increased risk of pleural mesothelioma was indicated for the highest versus lowest tertile of average intensity of asbestos (HR=1.21, 95% CI: 0.57 to 2.54). Pre-offshore asbestos exposure (vs no such exposure) was associated with increased risk of pleural mesothelioma (HR=2.06, 95% CI: 1.11 to 3.81). For offshore workers with no pre-offshore asbestos exposure, an increased risk of pleural mesothelioma was found for the highest tertile of average intensity of asbestos (HR=4.13, 95% CI: 0.93 to 18), versus the lowest tertile. No associations were found between RCF and pleural mesothelioma. CONCLUSIONS: Associations between JEM-based offshore asbestos exposure and pleural mesothelioma were confirmed in the NOPW cohort. Pleural mesothelioma risk was also associated with asbestos exposure before work in the offshore petroleum industry.

Narrative review of occupational exposures and noncommunicable diseases.

OBJECTIVE: Within the scope of the Exposome Project for Health and Occupational Research on applying the exposome concept to working life health, we aimed to provide a broad overview of the status of knowledge on occupational exposures and associated health effects across multiple noncommunicable diseases (NCDs) to help inform research priorities. METHODS: We conducted a narrative review of occupational risk factors that can be considered to have "consistent evidence for an association," or where there is "limited/inadequate evidence for an association" for 6 NCD groups: nonmalignant respiratory diseases; neurodegenerative diseases; cardiovascular/metabolic diseases; mental disorders; musculoskeletal diseases; and cancer. The assessment was done in expert sessions, primarily based on systematic reviews, supplemented with narrative reviews, reports, and original studies. Subsequently, knowledge gaps were identified, e.g. based on missing information on exposure-response relationships, gender differences, critical time-windows, interactions, and inadequate study quality. RESULTS: We identified over 200 occupational exposures with consistent or limited/inadequate evidence for associations with one or more of 60+ NCDs. Various exposures were identified as possible risk factors for multiple outcomes. Examples are diesel engine exhaust and cadmium, with consistent evidence for lung cancer, but limited/inadequate evidence for other cancer sites, respiratory, neurodegenerative, and cardiovascular diseases. Other examples are physically heavy work, shift work, and decision latitude/job control. For associations with limited/inadequate evidence, new studies are needed to confirm the association. For risk factors with consistent evidence, improvements in study design, exposure assessment, and case definition could lead to a better understanding of the association and help inform health-based threshold levels. CONCLUSIONS: By providing an overview of knowledge gaps in the associations between occupational exposures and their health effects, our narrative review will help setting priorities in occupational health research. Future epidemiological studies should prioritize to include large sample sizes, assess exposures prior to disease onset, and quantify exposures. Potential sources of biases and confounding need to be identified and accounted for in both original studies and systematic reviews.

Early life exposures contributing to accelerated lung function decline in adulthood - a follow-up study of 11,000 adults from the general population.

Background: We aimed to assess whether exposure to risk factors in early life from conception to puberty continue to contribute to lung function decline later in life by using a pooled cohort comprising approx. 11,000 adults followed for more than 20 years and with up to three lung function measurements. Methods: Participants (20-68 years) in the ECRHS and NFBC1966 cohort studies followed in the periods 1991-2013 and 1997-2013, respectively, were included. Mean annual decline in maximum forced expired volume in 1 s (FEV1) and forced vital capacity (FVC) were main outcomes. Associations between early life risk factors and change in lung function were estimated using mixed effects linear models adjusted for sex, age, FEV1, FVC and height at baseline, accounting for personal smoking. Findings: Decline in lung function was accelerated in participants with mothers that smoked during pregnancy (FEV1 2.3 ml/year; 95% CI: 0.7, 3.8) (FVC 2.2 ml/year; 0.2, 4.2), with asthmatic mothers (FEV1 2.6 ml/year; 0.9, 4.4) (FEV1/FVC 0.04 per year; 0.04, 0.7) and asthmatic fathers (FVC 2.7 ml/year; 0.5, 5.0), and in women with early menarche (FVC 2.4 ml/year; 0.4, 4.4). Personal smoking of 10 pack-years contributed to a decline of 2.1 ml/year for FEV1 (1.8, 2.4) and 1.7 ml/year for FVC (1.3, 2.1). Severe respiratory infections in early childhood were associated with accelerated decline among ever-smokers. No effect-modification by personal smoking, asthma symptoms, sex or cohort was found. Interpretation: Mothers' smoking during pregnancy, parental asthma and early menarche may contribute to a decline of FEV1 and FVC later in life comparable to smoking 10 pack-years. Funding: European Union's Horizon 2020; Research Council of Norway; Academy of Finland; University Hospital Oulu; European Regional Development Fund; Spanish Ministry of Science and Innovation; Generalitat de Catalunya.

Benzene exposure and risk of lung cancer in the Norwegian Offshore Petroleum Worker cohort: a prospective case-cohort study.

OBJECTIVE: The objective of our study was to examine whether occupational exposure to benzene is associated with lung cancer among males in the Norwegian Offshore Petroleum Workers cohort. METHODS: Among 25 347 male offshore workers employed during 1965-1998, we conducted a case-cohort study with 399 lung cancer cases diagnosed between 1999 and 2021, and 2035 non-cases sampled randomly by 5-year birth cohorts. Individual work histories were coupled to study-specific job-exposure matrices for benzene and other known lung carcinogens. Weighted Cox regression was used to estimate HRs and 95% CIs for the associations between benzene exposure and lung cancer, by major histological subtypes, adjusted for age, smoking and occupational exposure to welding fumes, asbestos and crystalline silica. Missing data were imputed. RESULTS: For lung cancer (all subtypes combined), HRs (95% CIs) for the highest quartiles of benzene exposure versus unexposed were 1.15 (0.61 to 2.35) for cumulative exposure, 1.43 (0.76 to 2.69) for duration, and 1.22 (0.68 to 2.18) for average intensity (0.280≤P-trend≤0.741). For 152 adenocarcinoma cases, a positive trend was observed for exposure duration (P-trend=0.044). CONCLUSIONS: In this cohort of offshore petroleum workers generally exposed to low average levels of benzene, we did not find an overall clear support for an association with lung cancer (all subtypes combined), although an association was suggested for duration of benzene exposure and adenocarcinoma. The limited evidence might be due to restricted statistical power.

Validation of a full-shift benzene exposure empirical model developed for work on offshore petroleum installations on the Norwegian continental shelf.

Workers on offshore petroleum installations might be exposed to benzene, a carcinogenic agent. Recently, a full-shift benzene exposure model was developed based on personal measurements. This study aimed to validate this exposure model by using datasets not included in the model. The exposure model was validated against an internal dataset of measurements from offshore installations owned by the same company that provided data for the model, and an external dataset from installations owned by another company. We used Tobit regression to estimate GM (geometric mean) benzene exposure overall and for individual job groups. Bias, relative bias, precision, and correlation were estimated to evaluate the agreement between measured exposures and the levels predicted by the model. Overall, the model overestimated exposure when compared to the predicted exposure level to the internal dataset with a factor of 1.7, a relative bias of 73%, a precision of 0.6, a correlation coefficient of 0.72 (p = 0.019), while the Lin's Concordance Correlation Coefficient (CCC) was 0.53. The model underestimated exposure when compared to the external dataset with a factor of about 2, with a relative bias of -45%, a precision of 1.2, a correlation coefficient of 0.31 (p = 0.544), and a Lin's CCC of 0.25. The exposure model overestimated benzene exposure in the internal validation dataset, while the precision and the correlation between the measured and predicted exposure levels were high. Differences in measurement strategies could be one of the reasons for the discrepancy. The exposure model agreed less with the external dataset.

Effects of Interventions to Prevent Work-Related Asthma, Allergy, and Other Hypersensitivity Reactions in Norwegian Salmon Industry Workers (SHInE): Protocol for a Pragmatic Allocated Intervention Trial and Related Substudies.

BACKGROUND: Workers in the salmon processing industry have an increased risk of developing respiratory diseases and other hypersensitivity responses due to occupational exposure to bioaerosols containing fish proteins and microorganisms, and related allergens. Little is known about effective measures to reduce bioaerosol exposure and about the extent of skin complaints among workers. In addition, while identification of risk factors is a core activity in disease prevention strategies, there is increasing interest in health-promoting factors, which is an understudied area in the salmon processing industry. OBJECTIVE: The overall aim of this ongoing study is to generate knowledge that can be used in tailored prevention of development or chronification of respiratory diseases, skin reactions, protein contact dermatitis, and allergy among salmon processing workers. The main objective is to identify effective methods to reduce bioaerosol exposure. Further objectives are to identify and characterize clinically relevant exposure agents, identify determinants of exposure, measure prevalence of work-related symptoms and disease, and identify health-promoting factors of the psychosocial work environment. METHODS: Data are collected during field studies in 9 salmon processing plants along the Norwegian coastline. Data collection comprises exposure measurements, health examinations, and questionnaires. A wide range of laboratory analyses will be used for further analysis and characterization of exposure agents. Suitable statistical analysis will be applied to the various outcomes of this comprehensive study. RESULTS: Data collection started in September 2021 and was anticipated to be completed by March 2023, but was delayed due to the COVID-19 pandemic. Baseline data from all 9 plants included 673 participants for the health examinations and a total of 869 personal exposure measurements. A total of 740 workers answered the study's main questionnaire on demographics, job characteristics, lifestyle, health, and health-promoting factors. Follow-up data collection is not completed yet. CONCLUSIONS: This study will contribute to filling knowledge gaps concerning salmon workers' work environment. This includes effective workplace measures for bioaerosol exposure reduction, increased knowledge on hypersensitivity, allergy, respiratory and dermal health, as well as health-promoting workplace factors. Together this will give a basis for improving the work environment, preventing occupational health-related diseases, and developing occupational exposure limits, which in turn will benefit employees, employers, occupational health services, researchers, clinicians, decision makers, and other stakeholders. TRIAL REGISTRATION: ClinicalTrials.gov NCT05039229; https://www.clinicaltrials.gov/study/NCT05039229. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48790.

Exposure to benzene and other hydrocarbons and risk of bladder cancer among male offshore petroleum workers.

BACKGROUND: Occupational exposures constitute the second leading cause of urinary bladder cancer after tobacco smoking. Increased risks have been found in the petroleum industry, but high-quality exposure data are needed to explain these observations. METHODS: Using a prospective case-cohort design, we analysed 189 bladder cancer cases (1999-2017) and 2065 randomly drawn non-cases from the Norwegian Offshore Petroleum Workers cohort. Cases were identified in the Cancer Registry of Norway, while work histories (1965-1998) and lifestyle factors were recorded by questionnaire at baseline (1998). Occupational petroleum-related hydrocarbon exposures were assessed by expert-developed job-exposure matrices. Hazard ratios were estimated by weighted Cox-regressions, adjusted for age, tobacco smoking, education, and year of first employment, and with lagged exposures. RESULTS: Increased risks were found in benzene-exposed workers, either long-term exposure (≥18.8 years, HR = 1.89, 95% CI: 1.14-3.13; p-trend = 0.044) or high-level cumulative benzene exposure (HR = 1.60, 95% CI: 0.97-2.63; p-trend = 0.065), compared with the unexposed. Associations persisted with 20-year exposure lag. No associations were found with skin or inhalation exposure to crude oil, mineral oil (lubrication, hydraulics, turbines, drilling), or diesel exhaust. CONCLUSIONS: The results suggest that exposures in the benzene fraction of the petroleum stream may be associated with increased bladder cancer risk.

Benzene Exposure From Selected Work Tasks on Offshore Petroleum Installations on the Norwegian Continental Shelf, 2002-2018.

OBJECTIVES: Work on offshore petroleum installations may cause exposure to benzene. Benzene is a carcinogenic agent, and exposure among workers should be as low as reasonably practicable. We aimed to assess short-term (less than 60 min) benzene exposure from the most frequent work tasks on offshore installations on the Norwegian continental shelf and identify determinants of exposure. In addition, we aimed to assess the time trend in task-based benzene measurements from 2002 to 2018. METHODS: The study included 763 task-based measurements with a sampling duration of less than 60 min, collected on 28 offshore installations from 2002 to 2018. The measurements were categorized into 10 different tasks. Multilevel mixed-effect Tobit regression models were developed for two tasks: sampling and disassembling/assembling equipment. Benzene source, season, indoors or outdoors, design of process area, year of production start, sampling method, and work operation were considered as potential determinants for benzene exposure in the models. RESULTS: The overall geometric mean (GM) benzene exposure was 0.02 ppm (95% confidence intervals 95%(CI: 0.01-0.04). The pipeline inspection gauge (PIG) operation task was associated with the highest exposure, with a GM of 0.33 ppm, followed by work on flotation cells, disassembling/assembling, and sampling, with GMs of 0.16, 0.04, and 0.01 ppm, respectively. Significant determinants for the disassembling/assembling task were work operation (changing or recertifying valves, changing or cleaning filters, and breaking pipes) and benzene source. For sampling, the benzene source was a significant determinant. Overall, the task-based benzene exposure declined annually by 10.2% (CI 95%: -17.4 to -2.4%) from 2002 to 2018. CONCLUSIONS: The PIG operation task was associated with the highest exposure out of the ten tasks, followed by work on flotation cells and when performing disassembling/assembling of equipment. The exposure was associated with the type of benzene source that was worked on. Despite the decline in task-based exposure in 2002-2018, technical measures should still be considered in order to reduce the exposure.

Correlated physical and mental health composite scores for the RAND-36 and RAND-12 health surveys: can we keep them simple?

BACKGROUND: The RAND-36 and RAND-12 (equivalent to versions 1 of the SF-36 Health Survey and SF-12 Health Survey, respectively) are widely used measures of health-related quality of life. However, there are diverging views regarding how to create the physical health and mental health composite scores of these questionnaires. We present a simple approach using an unweighted linear combination of subscale scores for constructing composite scores for physical and mental health that assumes these scores should be free to correlate. The aim of this study was to investigate the criterion validity and convergent validity of these scores. METHODS: We investigated oblique and unweighted RAND-36/12 composite scores from a random sample of the general Norwegian population (N = 2107). Criterion validity was tested by examining the correlation between unweighted composite scores and weighted scores derived from oblique principal component analysis. Convergent validity was examined by analysing the associations between the different composite scores, age, gender, body mass index, physical activity, rheumatic disease, and depression. RESULTS: The correlations between the composite scores derived by the two methods were substantial (r = 0.97 to 0.99) for both the RAND-36 and RAND-12. The effect sizes of the associations between the oblique versus the unweighted composite scores and other variables had comparable magnitudes. CONCLUSION: The unweighted RAND-36 and RAND-12 composite scores demonstrated satisfactory criterion validity and convergent validity. This suggests that if the physical and mental composite scores are free to be correlated, the calculation of these composite scores can be kept simple.

Occupational Benzene Exposure in the Norwegian Offshore Petroleum Industry, 2002-2018.

PURPOSE: Workers on offshore petroleum installations are at risk of being exposed to benzene which is carcinogenic to humans. The present study aimed to assess the time trend of full-shift benzene exposure from 2002 to 2018 in order to characterize benzene exposure among laboratory technicians, mechanics, process operators, and industrial cleaners, and to examine the possible determinants of benzene exposure. METHODS: A total of 924 measurements of benzene exposure from the Norwegian petroleum offshore industry were included. The median sampling duration was 680 min, ranging from 60 to 940 min. The overall geometric mean (GM) and 95% confidence interval, time trends, and determinants of exposure were estimated using multilevel mixed-effects tobit regression analyses. Time trends were estimated for sampling duration below and above 8 h, both overall and for job groups. The variability of exposure between installation and workers was investigated in a subset of data containing worker identification. RESULTS: The overall GM of benzene exposure was 0.004 ppm. When adjusting for job group, design of process area, season, wind speed, and sampling duration, industrial cleaners had the highest exposure (GM = 0.012). Laboratory technicians, mechanics, and process operators had a GM exposure of 0.004, 0.003, and 0.004 ppm, respectively. Overall, the measured benzene exposure increased by 7.6% per year from 2002 to 2018. Mechanics had an annual increase of 8.6% and laboratory technicians had an annual decrease of 12.6% when including all measurements. When including only measurements above 8 h, mechanics had an increase of 16.8%. No statistically significant time trend was found for process operators. Open process area, high wind speed, and wintertime were associated with reduced exposure level. CONCLUSIONS: An overall increase in measured exposure was observed from 2002 to 2018. The increase may reflect changes in measurement strategy from mainly measuring on random days to days with expected exposure. However, the time trend varied between job groups and was different for sampling duration above or below 8 h. Industrial cleaners had the highest exposure of the four job groups while no differences in exposure were observed between laboratory technicians, mechanics, and process operators. The design of the process area, job group, wind speed, and season were all significant determinants of benzene exposure.

Parental Prepuberty Overweight and Offspring Lung Function.

In a recent study we found that fathers' but not mothers' onset of overweight in puberty was associated with asthma in adult offspring. The potential impact on offspring's adult lung function, a key marker of general and respiratory health, has not been studied. We investigated the potential causal effects of parents' overweight on adult offspring's lung function within the paternal and maternal lines. We included 929 offspring (aged 18-54, 54% daughters) of 308 fathers and 388 mothers (aged 40-66). Counterfactual-based multi-group mediation analyses by offspring's sex (potential moderator) were used, with offspring's prepubertal overweight and/or adult height as potential mediators. Unknown confounding was addressed by simulation analyses. Fathers' overweight before puberty had a negative indirect effect, mediated through sons' height, on sons' forced expiratory volume in one second (FEV1) (beta (95% CI): -144 (-272, -23) mL) and forced vital capacity (FVC) (beta (95% CI): -210 (-380, -34) mL), and a negative direct effect on sons' FVC (beta (95% CI): -262 (-501, -9) mL); statistically significant effects on FEV1/FVC were not observed. Mothers' overweight before puberty had neither direct nor indirect effects on offspring's lung function. Fathers' overweight starting before puberty appears to cause lower FEV1 and FVC in their future sons. The effects were partly mediated through sons' adult height but not through sons' prepubertal overweight.

Night shift work, chemical coexposures and risk of female breast cancer in the Norwegian Offshore Petroleum Workers (NOPW) cohort: a prospectively recruited case-cohort study.

OBJECTIVES: This study examined the association between night shift work and risk of breast cancer, overall and by hormone receptor subtype, among females in the Norwegian Offshore Petroleum Workers (NOPW) cohort. We also examined the association of coexposure (chlorinated degreasers and benzene) and breast cancer risk, and possible interaction with work schedule. DESIGN: Prospectively recruited case-cohort study within the NOPW cohort. SETTING: Female offshore petroleum workers active on the Norwegian continental shelf. PARTICIPANTS: 600 female workers (86 cases and 514 non-cases) were included in the study. We excluded workers that died or emigrated before start of follow-up, had missing work history, were diagnosed with breast cancer or other prior malignancy (except non-melanoma skin cancer) before start of follow-up. RESULTS: No overall association was found between breast cancer risk and work schedule (HR 0.87, 95% CI 0.52 to 1.46 for work schedule involving night shift vs day shift only). There was no significant association between work schedule and risk of any breast cancer subtype. No significant interactions were found between work schedule and chemical coexposures (breast cancer overall Pinteraction chlorinated degreasers=0.725 and Pinteraction benzene=0.175). CONCLUSIONS: Our results did not provide supporting evidence that work schedule involving night shift affects breast cancer risk in female offshore petroleum workers, but should be considered cautiously due to few cases. Further studies with larger sample sizes are warranted.

The Exposome Approach in Allergies and Lung Diseases: Is It Time to Define a Preconception Exposome?

Emerging research suggests environmental exposures before conception may adversely affect allergies and lung diseases in future generations. Most studies are limited as they have focused on single exposures, not considering that these diseases have a multifactorial origin in which environmental and lifestyle factors are likely to interact. Traditional exposure assessment methods fail to capture the interactions among environmental exposures and their impact on fundamental biological processes, as well as individual and temporal factors. A valid estimation of exposure preconception is difficult since the human reproductive cycle spans decades and the access to germ cells is limited. The exposome is defined as the cumulative measure of external exposures on an organism (external exposome), and the associated biological responses (endogenous exposome) throughout the lifespan, from conception and onwards. An exposome approach implies a targeted or agnostic analysis of the concurrent and temporal multiple exposures, and may, together with recent technological advances, improve the assessment of the environmental contributors to health and disease. This review describes the current knowledge on preconception environmental exposures as related to respiratory health outcomes in offspring. We discuss the usefulness and feasibility of using an exposome approach in this research, advocating for the preconception exposure window to become included in the exposome concept.

Being overweight in childhood, puberty, or early adulthood: Changing asthma risk in the next generation?

BACKGROUND: Overweight status and asthma have increased during the last decades. Being overweight is a known risk factor for asthma, but it is not known whether it might also increase asthma risk in the next generation. OBJECTIVE: We aimed to examine whether parents being overweight in childhood, adolescence, or adulthood is associated with asthma in their offspring. METHODS: We included 6347 adult offspring (age, 18-52 years) investigated in the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) multigeneration study of 2044 fathers and 2549 mothers (age, 37-66 years) investigated in the European Community Respiratory Health Survey (ECRHS) study. Associations of parental overweight status at age 8 years, puberty, and age 30 years with offspring's childhood overweight status (potential mediator) and offspring's asthma with or without nasal allergies (outcomes) was analyzed by using 2-level logistic regression and 2-level multinomial logistic regression, respectively. Counterfactual-based mediation analysis was performed to establish whether observed associations were direct or indirect effects mediated through the offspring's own overweight status. RESULTS: We found statistically significant associations between both fathers' and mothers' childhood overweight status and offspring's childhood overweight status (odds ratio, 2.23 [95% CI, 1.45-3.42] and 2.45 [95% CI, 1.86-3.22], respectively). We also found a statistically significant effect of fathers' onset of being overweight in puberty on offspring's asthma without nasal allergies (relative risk ratio, 2.31 [95% CI, 1.23-4.33]). This effect was direct and not mediated through the offspring's own overweight status. No effect on offspring's asthma with nasal allergies was found. CONCLUSION: Our findings suggest that metabolic factors long before conception can increase asthma risk and that male puberty is a time window of particular importance for offspring's health.

Severe Occupational Asthma: Insights From a Multicenter European Cohort.

BACKGROUND: Although sensitizer-induced occupational asthma (OA) accounts for an appreciable fraction of adult asthma, the severity of OA has received little attention. OBJECTIVE: The aim of this study was to characterize the burden and determinants of severe OA in a large multicenter cohort of subjects with OA. METHODS: This retrospective study included 997 subjects with OA ascertained by a positive specific inhalation challenge completed in 20 tertiary centers in 11 European countries during the period 2006 to 2015. Severe asthma was defined by a high level of treatment and any 1 of the following criteria: (1) daily need for a reliever medication, (2) 2 or more severe exacerbations in the previous year, or (3) airflow obstruction. RESULTS: Overall, 162 (16.2%; 95% CI, 14.0%-18.7%) subjects were classified as having severe OA. Multivariable logistic regression analysis revealed that severe OA was associated with persistent (vs reduced) exposure to the causal agent at work (odds ratio [OR], 2.78; 95% CI, 1.50-5.60); a longer duration of the disease (OR, 1.04; 95% CI, 1.00-1.07); a low level of education (OR, 2.69; 95% CI, 1.73-4.18); childhood asthma (OR, 2.92; 95% CI, 1.13-7.36); and sputum production (OR, 2.86; 95% CI, 1.87-4.38). In subjects removed from exposure, severe OA was associated only with sputum production (OR, 3.68; 95% CI, 1.87-7.40); a low education level (OR, 3.41; 95% CI, 1.72-6.80); and obesity (OR, 1.98; 95% CI, 0.97-3.97). CONCLUSIONS: This study indicates that a substantial proportion of subjects with OA experience severe asthma and identifies potentially modifiable risk factors for severe OA that should be targeted to reduce the adverse impacts of the disease.

Determinants of airborne benzene evaporating from fresh crude oils released into seawater.

Benzene, toluene, ethylbenzene, xylenes, naphthalene and n-hexane evaporating from a thin oil film was measured for 30 min in a small-scale test system at 2 and 13 °C and the impact of physicochemical properties on airborne benzene with time after bulk oil release was studied. Linear mixed-effects models for airborne benzene in three time periods; first 5, first 15 and last 15 min of sampling, indicated that benzene content in fresh oil, oil group (condensate/light crude oil) and pour point were significant determinants explaining 63-73% of the total variance in the outcome variables. Oils with a high pour point evaporated considerably slower than oils with a low pour point. The mean air concentration of total volatile organic compounds was significatly higher at 13 °C (735 ppm) compared to 2 °C (386 ppm) immediately after release of oil, but at both temperatures the concentration rapidly declined.

Hypersensitivity pneumonitis in fish processing workers diagnosed by inhalation challenge.

Hypersensitivity pneumonitis may be caused by occupational exposure in the fish processing industry http://ow.ly/GbEf30lFnyk.

Maternal exposure to gasoline and exhaust increases the risk of childhood leukaemia in offspring - a prospective study in the Norwegian Mother and Child Cohort Study.

BACKGROUND: In the prospective population-based Norwegian Mother and Child Cohort Study (MoBa), comprising 113 754 offspring, we investigated the association between parental exposure to "gasoline or exhaust", as a proxy for benzene exposure, and childhood leukaemia. METHODS: Around gestational week 17, mothers and fathers responded to a questionnaire on exposure to various agents during the last 6 months and 6 months  pre-conception, respectively. Benzene exposure was assessed through self-reported exposure to "gasoline or exhaust". Cases of childhood leukaemia (n = 70) were identified through linkage with the Cancer Registry of Norway. Risk was estimated by hazard ratios (HRs) with 95% confidence intervals (95%CI), comparing offspring from exposed and unexposed parents using a Cox regression model. RESULTS: Maternal exposure to "gasoline or exhaust" was associated with an increased risk of childhood leukaemia (HR = 2.59; 95%CI: 1.03, 6.48) and acute lymphatic leukaemia (HR = 2.71; 95%CI: 0.97, 7.58). There was an increasing risk for higher exposure (p value for trend = 0.032 and 0.027). The association did not change after adjustment for maternal smoking. CONCLUSION: In spite of rather few cases, the findings in this prospective study, with the exposure metric defined a priori, support previous observations relating maternal exposure to benzene from gasoline and other petroleum-derived sources and the subsequent development of childhood leukaemia in the offspring.

Global Gene Expression Response in Peripheral Blood Cells of Petroleum Workers Exposed to Sub-Ppm Benzene Levels.

Altered gene expression in pathways relevant to leukaemogenesis, as well as reduced levels of circulating lymphocytes, have been reported in workers that were exposed to benzene concentrations below 1 ppm. In this study, we analysed whole blood global gene expression patterns in a worker cohort with altered levels of T cells and immunoglobulins IgM and IgA at three time points; pre-shift, post-shift (after three days), and post-recovery (12 hours later). Eight benzene exposed tank workers performing maintenance work in crude oil cargo tanks with a mean benzene exposure of 0.3 ppm (range 0.1⁻0.5 ppm) and five referents considered to be unexposed were examined by gene expression arrays. By using our data as independent validation, we reanalysed selected genes that were reported to be altered from previous studies of workers being exposed to sub-ppm benzene levels Four out of six genes previously proposed as marker genes in chronically exposed workers separated benzene exposed workers from unexposed referents (CLEC5, ACSL1, PRG2, IFNB1). Even better separation of benzene exposed workers and referents was observed for short-term exposure for genes in the Jak-STAT pathway, particularly elevated expression of IL6 and reduced expression of IL19.