Chimney sweeps in Sweden: a questionnaire-based assessment of long-term changes in work conditions, and current eye and airway symptoms

Personal exposure to gaseous and particulate phase polycyclic aromatic hydrocarbons (PAHs) and nanoparticles and lung deposited surface area (LDSA) for soot among Norwegian chimney sweepers

Exposure to polycyclic aromatic hydrocarbons (PAHs) of high molecular weight from chimney soot can cause cancer among chimney sweepers. These sweepers may also be exposed to high concentrations of nanosized particles, which can cause significant inflammatory responses due to their relatively greater surface area per mass. In this study, the authors aimed to assess the exposure profiles of airborne personal exposure to gaseous and particulate PAHs, and real-time samples of the particle number concentrations (PNCs), particle sizes, and lung-deposited surface areas (LDSAs), for chimney sweepers in Norway. Additionally, the authors aimed to assess the task-based exposure concentrations of PNCs, sizes, and LDSAs while working on different tasks. The results are based on personal samples of particulate PAHs (n = 68), gaseous PAHs (n = 28), and real-time nanoparticles (n = 8) collected from 17 chimney sweepers. Samples were collected during a "typical work week" of chimney sweeping and fire safety inspections, then during a "massive soot" week, where larger sweeping missions took place. Significantly higher PAH concentrations were measured during the "massive soot" week compared to the "typical work week," however, the time-weighted average (TWA) (8-hr) of all gaseous and particulate PAHs ranged from 0.52 to 4.47 µg/m3 and 0.49 to 2.50 µg/m3, respectively, well below the Norwegian occupational exposure limit (OEL) of 40 µg/m3. The PNCs were high during certain activities, such as emptying the vacuum cleaner. Additionally, during 2 days of sweeping in a waste sorting facility, the TWAs of the PNCs were 3.6 × 104 and 7.1 × 104 particles/cm3 on the first and second days, respectively, which were near and above the proposed nano reference limit TWA value of 4.0 × 104 particles/cm3 proposed by the International Workshop on Nano Reference Values. The corresponding TWAs of the LDSAs were 49.5 and 54.5 µm2/cm3, respectively. The chimney sweepers seemed aware of the potential health risks associated with exposure, and suitable personal protective equipment was used. However, the PNCs reported for the activities show that when the activities change or increase, the PNCs' TWAs can become unacceptably high.

Occupational exposure and the risk of airway obstruction and mortality

OBJECTIVES

To identify occupational groups at high risk of airway obstruction (AO) and mortality and potential interactions with smoking.

METHODS

Lung function data from the LuftiBus project were enriched with occupational and follow-up information from the Swiss National Cohort, resulting in a cohort of 10582 adults between 2000 and 2015. We assigned professions to occupational groups and estimated the risk of AO and mortality using adjusted logistic and Cox regression model. Additionally, we assessed multiplicative and additive interactions between occupational exposure and smoking.

RESULTS

Chimney sweeps and male workers from the agriculture, construction and food industries had an increased risk of AO (odds ratios ranging from 1.43 to 2.21). The risk of mortality was increased among male workers from the food industry (hazard ratio 1.57, 95% CI 1.10-2.23). Interactions with smoking were present in most associations, but smoking had no effect on the increased risk of mortality in the food industry.

CONCLUSIONS

Some occupational groups have a considerable risk of AO and mortality. The identification of the most affected occupations is of great importance enabling targeted risk reduction strategies.

Cancer-related proteins in serum are altered in workers occupationally exposed to polycyclic aromatic hydrocarbons: a cross-sectional study

Exposure to some polycyclic aromatic hydrocarbons (PAH) increases the risk of cancer and is common particularly for workers in occupations such as chimney sweeping. In exposed workers, screening of early cancer-related markers provides important information to identify individuals at risk. Here, we aimed to elucidate the associations between PAH exposure and serum levels of cancer-related proteins in 118 chimney sweeps and 126 occupationally unexposed controls, all non-smoking males from Sweden. Monoydroxylated metabolites of pyrene, phenanthrene, benzo[a]pyrene and benzo[a]anthracene were measured in urine using liquid chromatography coupled to tandem mass spectrometry and 90 cancer-related proteins were measured in serum using a proximity extension assay. Linear regression analysis adjusted for age and body mass index, and false discovery rate (FDR) identified 17 serum proteins that were differentially expressed (16 upregulated and 1 downregulated) in chimney sweeps compared with controls (FDR < 0.05). Concentrations of the peptidase kallikrein 13 (KLK13) showed significant positive associations with urinary concentrations of the PAH metabolites 3-hydroxybenzo[a]pyrene (3-OH-BaP) [B, 95% confidence interval (CI): 0.042, 0.008–0.076] and 3-hydroxybenzo[a]anthracene (3-OH-BaA) (B, 95% CI: 0.068, 0.002–0.134). Moreover, dose–response relationships were observed between KLK13 and 3-OH-BaP (trend test P = 0.027) and 3-OH-BaA (P = 0.035). Pathway and gene ontology analyses showed that cell movement, cell adhesion and cell migration were the predominant molecular functions associated with the top differentially expressed proteins. In conclusion, we found a number of putative cancer-related proteins differentially expressed in workers exposed to PAH. This warrants effective measure to reduce PAH exposure among workers as well as further investigation to confirm these findings.

Filaggrin variations are associated with PAH metabolites in urine and DNA alterations in blood

Dermal chemical exposure is common in many professions. The filaggrin protein is important for the skin barrier and variations in the filaggrin gene (FLG) may influence the uptake of chemicals via the skin, and consequently, the degree of systemic effects. The aim of this study was to investigate, in chimney sweeps with occupational exposure to polycyclic aromatic hydrocarbons (PAH) from soot, the influence of variation in FLG on internal PAH dose and DNA alterations, including epigenetic, previously linked to cancer and cardiovascular disease. We used TaqMan PCR to genotype 151 chimney sweeps and 152 controls for four FLG null variants (R501X, R2447X, S3247X and 2282del4) which cause impaired skin barrier, and FLG copy number variation (12th repeat, CNV12) which potentially is beneficial for the skin barrier. The internal dose of PAH was represented by urinary PAH metabolites (e.g. 1-hydroxypyrene and 3-hydroxybenzo[a]pyrene) that we measured by LC-MS/MS. We measured epigenetic alterations (methylation of AHRR and F2RL3) in blood by pyrosequencing; and DNA alterations (telomere length and mitochondrial DNA copy number) by real-time PCR. Hypomethylation of AHRR or F2RL3 is a risk factor for lung cancer and shorter telomere length a risk factor for cardiovascular disease. The frequencies of FLG null were 8.6 and 11.8% (p = 0.35), and CNV12 27.8 and 19.7% (p = 0.09) in chimney sweeps and controls, respectively. We found that among chimney sweeps working predominately with soot sweeping (high PAH exposure), CNV12 carriers had lower concentrations of PAH metabolites in urine compared with non-carriers (median 1-hydroxypyrene = 0.37 vs 0.86 μg/g creatinine respectively; p = 0.025 by linear regression models adjusted for age, BMI and smoking) compared to sweeps not carrying CNV12. Further, FLG null was associated with approximately 2.5% higher methylation of F2RL3 (cg03636183, p = 0.019 after adjustment for exposure group, age, BMI and smoking). FLG null was associated with approximately 7% shorter telomere length (p = 0.015, adjusted model). Our results suggest that FLG variations may influence the dose of PAH in highly exposed workers, possibly via dermal uptake. It also suggests that FLG variation may influence the degree of (epi)genotoxicity in the body. FLG variation is common in the working population and should be considered in risk assessment.

Effects of environment pollution on the ocular surface

The twenty-first century is fraught with dangers like climate change and pollution, which impacts human health and mortality. As levels of pollution increase, respiratory illnesses and cardiovascular ailments become more prevalent. Less understood are the eye-related complaints, which are commonly associated with increasing pollution. Affected people may complain of irritation, redness, foreign body sensation, tearing, and blurring of vision. Sources of pollution are varied, ranging from gases (such as ozone and NO₂) and particulate matter produced from traffic, to some other hazards associated with indoor environments. Mechanisms causing ocular surface disease involve toxicity, oxidative stress, and inflammation. Homeostatic mechanisms of the ocular surface may adapt to certain chronic changes in the environment, so affected people may not always be symptomatic. However there are many challenges associated with assessing effects of air pollution on eyes, as pollution is large scale and difficult to control. Persons with chronic allergic or atopic tendencies may have a pre-existing state of heightened mucosal immune response, hence they may have less tolerance for further environmental antigenic stimulation. It is beneficial to identify vulnerable people whose quality of life will be significantly impaired by environmental changes and provide counter measures in the form of protection or treatment. Better technologies in monitoring of pollutants and assessment of the eye will facilitate progress in this field.

Diagnosis, monitoring and prevention of exposure-related non-communicable diseases in the living and working environment: DiMoPEx-project is designed to determine the impacts of environmental exposure on human health

The WHO has ranked environmental hazardous exposures in the living and working environment among the top risk factors for chronic disease mortality. Worldwide, about 40 million people die each year from noncommunicable diseases (NCDs) including cancer, diabetes, and chronic cardiovascular, neurological and lung diseases. The exposure to ambient pollution in the living and working environment is exacerbated by individual susceptibilities and lifestyle-driven factors to produce complex and complicated NCD etiologies. Research addressing the links between environmental exposure and disease prevalence is key for prevention of the pandemic increase in NCD morbidity and mortality. However, the long latency, the chronic course of some diseases and the necessity to address cumulative exposures over very long periods does mean that it is often difficult to identify causal environmental exposures. EU-funded COST Action DiMoPEx is developing new concepts for a better understanding of health-environment (including gene-environment) interactions in the etiology of NCDs. The overarching idea is to teach and train scientists and physicians to learn how to include efficient and valid exposure assessments in their research and in their clinical practice in current and future cooperative projects. DiMoPEx partners have identified some of the emerging research needs, which include the lack of evidence-based exposure data and the need for human-equivalent animal models mirroring human lifespan and low-dose cumulative exposures. Utilizing an interdisciplinary approach incorporating seven working groups, DiMoPEx will focus on aspects of air pollution with particulate matter including dust and fibers and on exposure to low doses of solvents and sensitizing agents. Biomarkers of early exposure and their associated effects as indicators of disease-derived information will be tested and standardized within individual projects. Risks arising from some NCDs, like pneumoconioses, cancers and allergies, are predictable and preventable. Consequently, preventative action could lead to decreasing disease morbidity and mortality for many of the NCDs that are of major public concern. DiMoPEx plans to catalyze and stimulate interaction of scientists with policy-makers in attacking these exposure-related diseases.

Early markers of cardiovascular disease are associated with occupational exposure to polycyclic aromatic hydrocarbons

Occupational exposure to soot, rich in polycyclic aromatic hydrocarbons (PAH), has been associated with increased risk of cardiovascular disease (CVD). However, our knowledge about PAH exposure and early markers of CVD remains limited. In this cross-sectional study of 151 chimney sweeps and 152 controls, we investigated occupational exposure to PAH and early markers of CVD. Blood pressure (BP) (chimney sweeps only), urinary PAH metabolites and serum biomarkers were measured (C-reactive protein, homocysteine, gamma-glutamyltransferase, cholesterol, HDL, LDL, and triglycerides). Chimney sweeps had up to 7 times higher concentrations of PAH metabolites in urine than controls (P < 0.001): median concentrations (adjusted for specific gravity) for 1-hydroxypyrene, 2-hydroxyphenanthrene, 3-hydroxybenzo[a]pyrene, and 3-hydroxybenzo[a]anthracene were 0.56 µg/L, 0.78 µg/L, 4.75 ng/L, and 6.28 ng/L, respectively. Compared with controls, chimney sweeps had increased homocysteine, cholesterol, and HDL (β = 3.4 µmol/L, 0.43 mmol/L, and 0.13 mmol/L, respectively, P ≤ 0.003, adjusted for age, BMI, and smoking). In chimney sweeps, PAH metabolites correlated positively with the percentage of soot sweeping (P < 0.001). 2-hydroxyphenanthrene, 3-hydroxybenzo[a]pyrene, and 3-hydroxybenzo[a]anthracene were positively associated with diastolic BP (P < 0.044, adjusted for age, BMI, and smoking). PAH exposure among chimney sweeps resulted in elevated levels of markers for CVD risk. These findings stress the need to reduce occupational exposure to PAH.