Occupational exposure to combustion products rich in polycyclic aromatic hydrocarbons and particles is associated with an increased risk of lung cancer. This study aimed to evaluate whether the risk depended on the age at which the individuals were exposed.
Data from 1042 lung cancer cases and 2364 frequency-matched population controls selected from all men aged 40-75 years residing in Stockholm County, Sweden, at any time between 1985 and 1990, included detailed questionnaire information on occupational, residential, and smoking history. Occupational exposures were assessed by an occupational hygienist, and exposure to air pollution from road traffic was estimated based on dispersion models.
We found that individuals exposed to combustion products in their twenties were at higher risk than those never exposed (adjusted OR = 1.46; 95% CI 1.02, 2.10). The association was still evident after adjusting for a number of potential confounders, including lifetime cumulative exposure and latency. No clear association was found in those exposed at older ages.
Exposure to combustion products at a young age was associated with elevated risk of lung cancer. Exposure-reduction programs should be aware of the susceptibility of the younger employees.
In a population-based case-referent study of lung cancer we wanted to estimate the over-all influence on the lung cancer incidence from several occupational exposures. Standard methods to do this are based on addition of separately estimated attributable fractions (AFs) by rather complex formulas. Although a simple and valid method for direct estimation of summary effects was published in 1990, it is not well known and has rarely been used. We here describe the method and apply it to the data from the case-referent study. The AF for withdrawal of occupational exposure to both asbestos and combustion products were nearly identical regardless of if it was calculated by an algorithm for summation of AF for the exposure factors separately (6.90%), by a bootstrap method (6.89%, 95% confidence interval, CI: 3.69, 10.04), or by the simple 'dichotomization'-method (6.88%, 95%CI: 3.81, 9.84). The method is very easy to apply to population-based case-referent studies analyzed by logistic regression.
We examined cancer incidence in an expanded cohort of Swedish chimney sweeps.
We added male chimney sweep trade union members (1981-2006) to an earlier cohort (employed 1918-1980) and linked them to nationwide registers of cancer, causes of deaths, and total population. The total cohort (n = 6320) was followed from 1958 through 2006. We estimated standardized incidence ratios (SIRs) using the male Swedish population as reference. We estimated exposure as years of employment and analyzed for exposure-response associations by Poisson regression.
A total of 813 primary cancers were observed versus 626 expected (SIR = 1.30; 95% confidence interval = 1.21, 1.39). As in a previous follow-up, SIRs were significantly increased for cancer of the esophagus, liver, lung, bladder, and all hematopoietic cancer. New findings included significantly elevated SIRs for cancer of the colon, pleura, adenocarcinoma of the lung, and at unspecified sites. Total cancer and bladder cancer demonstrated positive exposure-response associations.
Exposure to soot and asbestos are likely causes of the observed cancer excesses, with contributions from adverse lifestyle factors. Preventive actions to control work exposures and promote healthier lifestyles are an important priority.
Work in chemical laboratories is associated with exposure to chemicals, of which some are known or suspected carcinogens. A cohort study of laboratory workers in Stockholm followed until 1992 showed an excess of hematolymphatic malignancies in chemical laboratories and an excess of breast cancer among women working for more than 10 years in such laboratories. The follow-up of this cohort has now been extended by 20 years.
The cohort comprised 2245 female laboratory workers who are employed for >1?year from 1950 to 1989. Information on employment periods and type of laboratory ('chemical' or 'non-chemical') was obtained from employee registers. Cancer diagnoses from 1958 to 2012 were obtained from the Swedish Cancer Registry.
There were 383 cases of cancer (SIR=0.93 (95% CI 0.84 to 1.02)). The risk of breast cancer was elevated, of borderline statistical significance, among those who had worked for at least 10 years in chemical laboratories (SIR=1.41 (95% CI 0.99 to 1.95) 36 cases). The breast cancer risk was especially high in women who had worked for more than 10 years in chemical labs before 1970 (SIR=3.76 (95% CI 1.72 to 7.14), nine cases). There was no excess of breast cancer in non-chemical labs (SIR=0.77 (95% CI 0.54 to 1.07), 35 cases). The number of hematolymphatic cancer was no longer significantly elevated.
The increased risk of breast cancer, as well as the earlier noted excess of hematolymphatic malignancies, may be related to exposure to carcinogenic chemicals/organic solvents (eg, benzene) used in chemical laboratories, especially during earlier periods.
To explore chimney sweeping work tasks, chimney sweeps' use of protective equipment, and type of fuel used by clients, over time. Further, to assess work-relatedness of current eye and airway symptoms.
In a cross-sectional study in 2011, male Swedish chimney sweeps (n = 483; age 21-69 years) answered a questionnaire about their occupational history and eye and airway symptoms.
Between 1960 and 2010, black-soot-sweeping in private homes was the major task, although it decreased during the time period, for chimney sweeps. Between 1975 and 2010, the use of petroleum oil decreased, whereas the use of pellets and wood increased. Also, the use of gloves and masks increased significantly. Black-soot-sweeping in industry was associated with work-related eye symptoms (prevalence odds ratio POR = 3.76, 95% CI: 1.72-8.24, for every 10% increment of working time, adjusted for age and tobacco smoking). Chimney sweeps also had slightly higher prevalence of cough with increasing black-soot-sweeping (POR = 1.06, 95% CI: 0.99-1.13 for every 10% increment, further adjusted for the use of mask), and the association was more pronounced, although nonsignificant, for black-soot-sweeping in industry (adjusted POR = 1.26, 95% CI: 0.98-1.61).
Chimney sweeping tasks and use of protective equipment as well as type of fuel used by the clients changed significantly over the last 35 years, which may have changed chimney sweeps' exposure to soot. Still, chimney sweeps in Sweden have black-soot-sweeping-related eye and airway symptoms.
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Lung cancer is mainly caused by smoking, but the quantitative relations between smoking and histologic subtypes of lung cancer remain inconclusive. By using one of the largest lung cancer datasets ever assembled, we explored the impact of smoking on risks of the major cell types of lung cancer. This pooled analysis included 13,169 cases and 16,010 controls from Europe and Canada. Studies with population controls comprised 66.5% of the subjects. Adenocarcinoma (AdCa) was the most prevalent subtype in never smokers and in women. Squamous cell carcinoma (SqCC) predominated in male smokers. Age-adjusted odds ratios (ORs) were estimated with logistic regression. ORs were elevated for all metrics of exposure to cigarette smoke and were higher for SqCC and small cell lung cancer (SCLC) than for AdCa. Current male smokers with an average daily dose of >30 cigarettes had ORs of 103.5 (95% confidence interval (CI): 74.8-143.2) for SqCC, 111.3 (95% CI: 69.8-177.5) for SCLC and 21.9 (95% CI: 16.6-29.0) for AdCa. In women, the corresponding ORs were 62.7 (95% CI: 31.5-124.6), 108.6 (95% CI: 50.7-232.8) and 16.8 (95% CI: 9.2-30.6), respectively. Although ORs started to decline soon after quitting, they did not fully return to the baseline risk of never smokers even 35 years after cessation. The major result that smoking exerted a steeper risk gradient on SqCC and SCLC than on AdCa is in line with previous population data and biological understanding of lung cancer development.
BACKGROUND: Few occupational studies have addressed melanoma in women. Accordingly, our aim was to identify occupations with higher risk of cutaneous melanoma, overall and by site, in Swedish female workers. METHODS: All gainfully employed Swedish women were followed-up from 1971 to 1989, using Death/Cancer Registers. Occupational risk ratios adjusted for age, period, town size, and geographic zone were computed for each site. Risk patterns for different sites were then compared. RESULTS: High risks were observed among educators, bank tellers, dental nurses, librarians/archivists/curators, horticultural workers, and hatmakers/milliners. Telephone operators and textile workers had increased risk, mainly in the leg. Other occupation-specific site excesses were also found. Upper-limb risks were correlated with head/neck and thorax, though these two sites were not associated. Legs registered a special pattern, with a moderate correlation with upper limbs or thorax, and no correlation with head/neck. CONCLUSIONS: Some occupations with possible exposure to arsenic/mercury displayed increased risk. The generalized excess risk among hatmakers/milliners warrants further attention. The weak correlation between legs and other sites suggests site specificity in melanoma risk factors.
Some polycyclic aromatic hydrocarbons (PAH) are known carcinogens and workplace PAH exposure may increase the risk of cancer. Monitoring early cancer-related changes can indicate whether the exposure is carcinogenic. Here, we enrolled 151 chimney sweeps, 152 controls and 19 creosote-exposed male workers from Sweden. We measured urinary PAH metabolites using LC/MS/MS, the cancer-related markers telomere length (TL) and mitochondrial DNA copy number (mtDNAcn) using qPCR, and DNA methylation of lung cancer-related genes F2RL3 and AHRR using pyrosequencing. The median 1-hydroxypyrene (PAH metabolite) concentrations were highest in creosote-exposed workers (8.0 µg/g creatinine) followed by chimney sweeps (0.34 µg/g creatinine) and controls (0.05 µg/g creatinine). TL and mtDNAcn did not differ between study groups. Chimney sweeps and creosote-exposed workers had significantly lower methylation of AHRR CpG site cg05575921 (88.1 and 84.9%, respectively) than controls (90%). Creosote-exposed workers (73.3%), but not chimney sweeps (76.6%) had lower methylation of F2RL3 cg03636183 than controls (76.7%). Linear regression analyses showed that chimney sweeps had lower AHRR cg05575921 methylation (B = -2.04; P
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?
Diesel motor exhaust is classified by the International Agency for Research on Cancer as probably carcinogenic to humans. The epidemiologic evidence is evaluated as limited because most studies lack adequate control for potential confounders and only a few studies have reported on exposure-response relationships.
Investigate lung cancer risk associated with occupational exposure to diesel motor exhaust, while controlling for potential confounders.
The SYNERGY project pooled information on lifetime work histories and tobacco smoking from 13,304 cases and 16,282 controls from 11 case-control studies conducted in Europe and Canada. A general population job exposure matrix based on ISCO-68 occupational codes, assigning no, low, or high exposure to diesel motor exhaust, was applied to determine level of exposure.
Odds ratios of lung cancer and 95% confidence intervals were estimated by unconditional logistic regression, adjusted for age, sex, study, ever-employment in an occupation with established lung cancer risk, cigarette pack-years, and time-since-quitting smoking. Cumulative diesel exposure was associated with an increased lung cancer risk highest quartile versus unexposed (odds ratio 1.31; 95% confidence interval, 1.19-1.43), and a significant exposure-response relationship (P value
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