Occupational and Environmental Health

Petrol exposure and DNA integrity of peripheral lymphocytes Abstract Purpose To determine the effect of petrol exposure on DNA integrity in peripheral blood lymphocytes among petrol attendants and a non-exposed comparison population. Methods This cross-sectional study included 101 fuel station employees and 50 office-based non-exposed workers in Durban, South Africa. Participants were interviewed using a validated questionnaire. Genomic DNA was extracted from peripheral lymphocytes for the benzo(a)pyrene diol epoxide (BPDE)-DNA adduct assay (ELISA), and DNA damage was determined using the comet assay and reported as percentage tail DNA. Results The exposed (n = 101) and non-exposed participants (n = 50) varied with regard to age, housing, smoking, and proximity to industry and petrol stations. Among the exposed, the mean duration of employment in the fuel industry was 5.8 years (SD = 4.6), and among those pumping fuel (n = 75), the mean metric tons of petrol pumped in the past 12 months per worker was 199.2 (SD = 88.9). The mean percentage tail DNA varied significantly between exposed and non-exposed groups: 23.8 % (SD = 13.3) and 8.1 % (SD = 1.8) (p < 0.01), respectively. A significant difference existed between the groups for BPDE-DNA adducts: 30.0 ng/ml (SD = 12.7) and 18.1 ng/ml (SD = 18.2) (p < 0.0001), respectively. Regression models, adjusting for cigarette smoking, age, and sex, showed a 16.5 greater percentage tail DNA among the exposed compared to non-exposed (95 % CI 11.8–21.1 %), while the exposed group had a 12.9 ng/ml greater increase in BPDE-DNA adducts has compared to the unexposed (95 % CI 7.2–18.7 ng/ml). Cigarette smoking resulted in almost a 3.5 % increase in percentage tail DNA. Conclusion Our study adds to the literature that long-term, low-dose exposure to vehicular fuels is likely to result in altered DNA integrity and genotoxicity among petrol attendants. These results strengthen the case that these workers must be afforded appropriate protection to prevent serious adverse outcomes.

Möhner 2015: the suggested approach does not correct for competing causes reliably and overstates SMRs

Biomarkers of inflammation in workers exposed to compost and sewage dust Abstract Purpose The association between exposure during handling of sewage and compost and the serum concentration of inflammatory biomarkers was studied. Methods A total of 44 workers exposed to sewage dust, 47 workers exposed to compost dust and 38 referents from the administrative staff participated. Microbial aerosols were collected by personal inhalable samplers. The concentrations of bacterial cells, spores from fungi and bacteria (actinomycetes) and endotoxins were determined by fluorescence and scanning electron microscopy and the Limulus assay. Fibrinogen, D-dimer, ICAM-1, VCAM-1 and IL-6 were determined by ELISA and C-reactive protein (CRP) by HS-MicroCRP assay in blood samples collected post-shift. Results The exposure to dust ranged from 0.02 to 11 mg/m3, endotoxins from 1 to 3160 EU/m3 and bacteria from 0 to 209 × 106 cells/m3. Fungal (0–41 × 106 spores/m3) and actinomycetes spores (0–590 × 106 actinomycetes spores/m3) were observed only at compost plants. The exposed workers had significantly higher fibrinogen (arithmetic mean 3.3 mg/ml) and CRP (geometric mean 1.5 mg/L) compared to the referents (2.8 and 1.0 mg/L, respectively). The serum concentration of CRP was negatively associated with forced expiratory volume in one second (FEV1) in  % of predicted. Exposure to inhalable dust and bacteria was positively associated with the serum concentration of ICAM-1. Conclusions This study suggests that exposure to bacteria and dust when handling sewage and compost may initiate an inflammation shown by an increase in serum concentration of ICAM-1. The higher concentrations of fibrinogen and CRP in exposed workers compared to the referents may reflect a low-grade systemic inflammation.

Response to the letter to the editor from Morfeld

Temporal patterns of sitting at work are associated with neck–shoulder pain in blue-collar workers: a cross-sectional analysis of accelerometer data in the DPHACTO study Abstract Background Our aim was to examine the extent to which temporal patterns of sitting during occupational work and during leisure-time, assessed using accelerometry, are associated with intense neck–shoulder pain (NSP) in blue-collar workers. Methods The population consisted of 659 Danish blue-collar workers. Accelerometers were attached to the thigh, hip, trunk and upper dominant arm to measure sitting time and physical activity across four consecutive days. Temporal sitting patterns were expressed separately for work and leisure by the proportion of total time spent sitting in brief bursts (0–5 min), moderate (>5–20 min) and prolonged (>20 min) periods. The peak NSP intensity during the previous 3 months was assessed using a numerical rating scale (range 0–10) and dichotomized into a lower (≤4) and higher (>4) NSP score. Logistic regression analyses with multiple adjustments for individual and occupational factors were performed to determine the association between brief, moderate and prolonged sitting periods, and NSP intensity. Results Time in brief bursts of occupational sitting was negatively associated with NSP intensity (adjusted OR 0.68, 95 % CI 0.48–0.98), while time in moderate periods of occupational sitting showed a positive association with NSP (adjusted OR 1.32, 95 % CI 1.04–1.69). Time in prolonged periods of occupational sitting was not associated with NSP (adjusted OR 0.78, 95 % CI 0.78–1.09). We found no significant association between brief, moderate or prolonged sitting periods during leisure, and NSP. Conclusion Our findings indicate that the association between occupational sitting time and intense NSP among blue-collar workers is sensitive to the temporal pattern of sitting.

No evidence of cardiovascular toxicity in workers exposed below 5 ppm carbon disulfide Abstract Purpose Carbon disulfide (CS2), used in the viscose process, is well known for having multiple health effects, including on the cardiovascular system, in workers with long-term exposure higher than 10 ppm. The mechanisms of those effects are, however, not precisely defined, and it remains uncertain whether cardiovascular toxicity may occur at exposure levels lower than 10 ppm. Therefore, the purpose of this study is to explore the health impact of low CS2 exposure levels using an array of preclinical biomarkers of cardiovascular risk. Methods Exposure intensity was determined by measuring urinary 2-thiothiazolidine-4-carboxylic acid (TTCA) in 117 workers from two plants using the viscose process, sampled in multiples phases (2003, 2006 and 2013). A cumulative exposure index (CEI) and a recent exposure index (REI) were calculated for each worker, and shiftwork was documented to account for potential confounding. Cardiovascular parameters included blood pressure, total, LDL and HDL cholesterol, triglycerides, C-reactive protein dosed in serum with high sensitivity (HsCRP), N-terminal pro-brain natriuretic peptide, and albuminuria/creatininuria ratio (UACR). Potential biological confounders were fasting blood glucose and serum creatinine. Bivariate and multivariate regression analyses were used to trace relationships between cardiovascular risk biomarkers and other variables, including CEI, REI and shiftwork duration. Results Median REI and CEI were 0.05 mg TTCA/g creat and 21.5 mg TTCA/g creat*months, respectively. While expected associations, such as between HsCRP and LDL Cholesterol, were found, significant associations between cardiovascular risk markers and CS2 exposure indexes (CEI or REI) were not detected. Shiftwork duration was positively associated with UACR in workers with elevated fasting blood glucose. Conclusion In practice, when CS2 exposure levels are kept below 5 ppm (TTCA < 2.2 mg/g creat), it does not appear useful to perform a systematic monitoring of total serum cholesterol or its subfractions, or of the new biomarkers of cardiovascular risk (NTproBNP, HsCRP, UACR) investigated in the present study. It appears important to carefully monitor the existence of diabetes that may justify avoiding shiftwork.

Inflammatory markers and exposure to airborne particles among workers in a Swedish pulp and paper mill Abstract Purpose To study the relationship between exposure to airborne particles in a pulp and paper mill and markers of inflammation and coagulation in blood. Methods Personal sampling of inhalable dust was performed for 72 subjects working in a Swedish pulp and paper mill. Stationary measurements were used to study concentrations of total dust, respirable dust, PM10 and PM2.5, the particle surface area and the particle number concentrations. Markers of inflammation, interleukins (IL-1b, IL-6, IL-8, and IL-10), C-reactive protein (CRP), serum amyloid A (SAA), and fibrinogen and markers of coagulation factor VIII, von Willebrand, plasminogen activator inhibitor, and D-dimer were measured in plasma or serum. Sampling was performed on the last day of the work free period of 5 days, before and after the shift the first day of work and after the shifts the second and third day. In a mixed model analysis, the relationship between particulate exposures and inflammatory markers was determined. Sex, age, smoking, and BMI were included as covariates. Results The average 8-h time-weighted average (TWA) air concentration levels of inhalable dust were 0.30 mg/m3, range 0.005–3.3 mg/m3. The proxies for average 8-h TWAs of respirable dust were 0.045 mg/m3. Significant and consistent positive relations were found between several exposure metrics (PM 10, total and inhalable dust) and CRP, SAA and fibrinogen taken post-shift, suggesting a dose–effect relationship. Conclusion This study supports a relationship between occupational particle exposure and established inflammatory markers, which may indicate an increased risk of cardiovascular disease.

Occupational exposure in the removal and disposal of asbestos-containing materials in Italy Abstract Purpose A great variety of asbestos-containing materials are present in both residential and work settings because of the widespread use made in the past, and many occupational activities still entail the risk of asbestos exposure in Italy, more than 2 decades after the total national ban, mainly those involved in the removal and disposal of asbestos. The aim of the study was to evaluate the level and extent of asbestos exposure in Italy between the years 1996–2013 in the sector of asbestos abatement. Methods Data were collected from firm registries of asbestos-exposed workers and descriptive statistics were calculated for exposure-related variables. Results Overall, 15,860 measurements of asbestos exposure were selected from the national database of registries, mostly referring to the construction sector (N = 11,353). Despite the mean exposure levels are low, the air concentration of asbestos fibers measured during these activities may overcome the action level established by the Italian legislation and, in a limited number of cases, can exceed even the occupational limit value. Among occupations at higher risk, there are also garbage collectors and insulation workers. Conclusions Starting from the analysis of the Italian database of occupational exposure registries, this study outlines the current levels of asbestos exposure in abatement-related sectors, discussing their possible implications for public health policies and surveillance programs.

Violence at work: forensic medical examination of police officers assaulted while on duty: comparisons with other groups of workers in two centres of the Paris area, 2010–2012 Abstract Purpose To test for differences in somatic, psychic and functioning outcomes associated with assaults across four groups of workers, of which three are structurally at high risk of occupational violence. To report and compare job characteristics, characteristics of the assault and medical findings in police officers and other workers at the time of a forensic examination performed shortly after they complained for being assaulted while working. Methods A two-centre prospective study recruiting adult survivors of workplace violence who lodged a complaint to the judicial authorities and were examined by forensic physicians in the Paris area, between 2010 and 2012 over a 27-month period, was conducted. Victims were administered a dedicated questionnaire and filled in the peritraumatic dissociative experiences questionnaire. Bivariate and multivariate analyses were performed on collected data to account for potential biases. Results Compared to employees of public transports services, private security guards and other workers, police officers were less likely to report psychic disturbances and peritraumatic dissociative experiences, despite adverse factors such as a worse external working climate or more frequent exposure to workplace assaults. No differences were observed in terms of somatic symptoms or functional impairment across groups. Conclusions Although structurally more exposed to adverse factors than other workers, police officers appeared to be more protected from negative outcomes. The reasons for this resilience should be more precisely investigated.

Does physical or psychosocial workload modify the effect of musculoskeletal pain on sickness absence? A prospective study among the Finnish population Abstract Aims Previously, among food industry workers, multisite pain predicted sickness absence (SA) only in those with low biomechanical workload. Here we studied among a wide range of occupations whether the relationship of pain with SA was modified by the level of physical or psychosocial workload. Methods A nationally representative sample (Health 2000 Survey) comprised 3420 occupationally active Finns aged 30–55 years. Baseline data on musculoskeletal pain during the preceding month, strenuous work history, current physical workload, job demands, job control, support at work, lifestyle, and chronic diseases were obtained in 2000/2001 by questionnaire, interview, and clinical examination. Musculoskeletal pain in 18 body locations was combined into four sites (neck, upper limbs, low back, and lower limbs) and classified as no pain, single-site pain, and multisite pain (2–4 sites). The data were linked with information from national registers on annual SA periods lasting ≥10 workdays for 2002–2008. Negative binomial regression analysis was used. Results At baseline, one-third of the study sample reported single-site and one-third multisite pain. Allowing for gender and age, the employees with multisite pain in strata with high physical workload and high job demands tended to have the highest risk of SA, but no statistically significant interactive effects between work factors and pain were observed. Further adjustment for health-related lifestyle and chronic diseases decreased the risk estimates in all strata. Conclusion We did not find evidence for significant modification by physical or psychosocial workload of the relationship between musculoskeletal pain and SA periods lasting ≥10 workdays.