Pål Graff

Occupational Exposure to Trichloramine and Trihalomethanes in Swedish Indoor Swimming Pools: Evaluation of Personal and Stationary Monitoring

Introduction: Chlorination is a method commonly used to keep indoor swimming pool water free from pathogens. However, chlorination of swimming pools produces several potentially hazardous by-products as the chlorine reacts with nitrogen containing organic matter. Up till now, exposure assessments in indoor swimming pools have relied on stationary measurements at the poolside, used as a proxy for personal exposure. However, measurements at fixed locations are known to differ from personal exposure. Methods: Eight public swimming pool facilities in four Swedish cities were included in this survey. Personal and stationary sampling was performed during day or evening shift. Samplers were placed at different fixed positions around the pool facilities, at ~1.5 m above the floor level and 0–1 m from the poolside. In total, 52 personal and 110 stationary samples of trichloramine and 51 personal and 109 stationary samples of trihalomethanes, were collected. Results: The average concentration of trichloramine for personal sampling was 71 µg m−3, ranging from 1 to 240 µg m−3 and for stationary samples 179 µg m−3, ranging from 1 to 640 µg m−3. The air concentrations of chloroform were well below the occupational exposure limit (OEL). For the linear regression analysis and prediction of personal exposure to trichloramine from stationary sampling, only data from personal that spent >50% of their workday in the pool area were included. The linear regression analysis showed a correlation coefficient (r 2) of 0.693 and a significant regression coefficient β of 0.621; (95% CI = 0.329–0.912, P = 0.001). Conclusion: The trichloramine exposure levels determined in this study were well below the recommended air concentration level of 500 µg m−3; a WHO reference value based on stationary sampling. Our regression data suggest a relation between personal exposure and area sampling of 1:2, implying an OEL of 250 µg m−3 based on personal sampling.

DNA-methylation of the cancer-related genes F2RL3 and AHRR is associated with occupational exposure to polycyclic aromatic hydrocarbons

This study showed that chimney sweeps and creosote workers had lower DNA methylation of F2RL3 and AHRR, which is a risk factor for lung cancer. PAH exposure from soot and creosote oil likely play a role in this epigenetic modification.

Risk of sarcoidosis and seropositive rheumatoid arthritis from occupational silica exposure in Swedish iron foundries: a retrospective cohort study

Objective To study the impact of occupational silica exposure on the incidence rates of sarcoidosis and rheumatoid arthritis (RA) in a cohort of exposed workers in Swedish iron foundries. Design The prevalence of sarcoidosis and RA in a cohort of silica exposed workers was compared with the prevalence in the general Swedish population in this register study. A mixed model was used to calculate silica exposure, and individual silica exposures were used to compute dose responses. Setting Personnel records from 10 iron foundries were used to identify workers whose employment began before 2005 which was then linked to the national non-primary outpatient visits register. Participants The final cohort consisted of 2187 silica-exposed male workers who had been employed for at least 1 year and were still alive without having emigrated when the follow-up study began. The cohort’s employment period covers 23 807 person-years at risk. Main outcome The presented results indicate that moderate to high levels of silica exposure increase risks for sarcoidosis and seropositive RA. Results Mean levels of airborne silica dust in the foundries decreased significantly between the 1970s and 2000s. Incidence rates of sarcoidosis (3.94; 95% CI 1.07 to 10.08) and seropositive RA (2.59; 95% CI 1.24 to 4.76) were significantly higher among highly exposed individuals. Conclusion Our results reveal increased risks for sarcoidosis and seropositive RA among individuals with high exposure to silica dust (>0.048 mg/m3) compared with non-exposed and less-exposed groups.

Silica exposure increases the risk of stroke but not myocardial infarction—A retrospective cohort study

Introduction Work-related exposure to silica is a global health hazard that causes diseases such as silicosis. Some studies have also reported that silica exposure is linked to elevated cardiovascular disease mortality. However, these diagnoses have not been investigated in detail and there have been few studies on morbidity. The aim of this study is to examine morbidity and mortality from different cardiovascular diseases among silica-exposed Swedish foundry workers. Methods Historical and contemporary measurements (1968–2006) of respiratory silica exposure were matched to job categories, individual foundries, and 4 time periods (1968–1979, 1980–1989, 1990–1999, 2000–2006) using a mixed model. Morbidity and mortality data for the studied cohorts were matched against the General Population Registry. Statistical analyses were performed with SPSS and STATA, and the data were stratified by age, gender, and year. Results Mortality from cardiovascular disease (SMR 1.3; 95% CI 1.2–1.4) and stroke (SMR 1.6, 95% CI 1.2–2.1) was significantly elevated among the studied population. The cohort also exhibited significantly elevated morbidity from stroke (SIR 1.34; 95% CI 1.2–1.5) but not myocardial infarction. The mean age at the time of first morbidity from stroke was 64 years, with 36% of the cases occurring before the age of 60. Conclusions Swedish foundry workers exposed to respirable silica exhibit elevated morbidity and mortality from stroke, but not from myocardial infarction. Our results also suggest a relationship between silica exposure and morbidity from stroke at a younger age than the general population.

715 Occupational exposure to trichloramine and trihalomethanes adverse health effects in rehabilitation swimming pools

Introduction Studies have shown that employees and visitors at indoor swimming pool facilities are experiencing symptoms in the nose and throat, eye irritation and, in some cases, asthma. Due to chlorination, byproduct such as trichloramine and trihalomethanes can be present in indoor swimming pool air. This exposure has not been described in rehabilitation swimming pools that normally consists of smaller facilities and use warmer water compared to ordinary swimming pools. Methods The occupational exposure of trichloramine and trihalomethanes in air has been studied at ten Swedish indoor swimming pool facilities. The study has also included the prevalence of ocular symptoms and symptoms and effects on the upper and lower respiratory tract. Nitrogen oxide (NO) in exhaled air has been investigated as a measure of early respiratory tract inflammation. Results The average trichloramine concentration for personal measurements (n=17) was 23 µg/m3, varying between 1 and 76 µg/m3. Corresponding stationary measurements (n=27) performed at the pool side showed an average concentration of 30 µg/m3, varying between 1 and 140 µg/m3. A WHO reference value for trichloramine, based on stationary measurements, is set to 500 µg/m3. The levels of trihalomethanes for both personal (n=20) and stationary (n=35) measurements were less than 1% of the Swedish OEL for chloroform. Measurements of NO in exhaled air showed a change during shift when exposed (n=23) and controls (n=50) were compared. Discussion Both personal and stationary measurements showed low levels of trichloramine and trihalomethanes. When comparing exposed and controls during shift, a difference of NO in exhaled air was noted.

716 Health effects from hand-arm vibrations in swedish mechanical industry

Background Working with handheld vibrating tools is common in the mechanical industry and one of the main causes of occupational disease in Sweden. There are several well-known effects on vascular, neurological and musculoskeletal symptoms in the hands from vibrations. Methods This report is based on medical examinations performed on 38 males at a mechanical industry. The medical examination consisted of questionnaires regarding symptoms and exposure, standardised medical examination and quantitative sensory testing (QST). The exposure to hand-arm vibrations was also measured. Blood samples were collected to investigate for biological markers for vibration exposure. Results 24% of the exposed subjects had vascular symptoms in form of Raynaud´s phenomenon, and 37% had increased cold intolerance. More common was neurological symptoms which affected nearly 60% of the exposed subject. Although the vibration exposure was not above the Swedish threshold limit of 5 m/s2, nearly 37% of those surveyed showed signs of carpal tunnel syndrome (CTS). Analysis of the biological markers in the blood samples will be performed soon. Conclusion This study shows that health effects from exposure to hand-arm vibration are common in the study group even if the vibration exposure is below the Swedish occupational threshold limit of 5 m/s2.

Occupational exposure to trichloramine and trihalomethanes: adverse health effects among personnel in habilitation and rehabilitation swimming pools

Abstract Personnel in swimming pool facilities typically experience ocular, nasal, and respiratory symptoms due to water chlorination and consequent exposure to disinfection by-products in the air. The aim of the study was to investigate exposure to trichloramine and trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) from the perspective of adverse health effects on the personnel at Swedish habilitation and rehabilitation swimming pools. The study included 10 habilitation and rehabilitation swimming pool facilities in nine Swedish cities. The study population comprised 24 exposed swimming pool workers and 50 unexposed office workers. Personal and stationary measurements of trichloramine and trihalomethanes in air were performed at all the facilities. Questionnaires were distributed to exposed workers and referents. Spirometry, fraction of exhaled nitric oxide (FENO), and peak expiratory flow (PEF) were measured. Personal and stationary measurements yielded trichloramine levels of 1–76 µg/m3 (average: 19 µg/m3) and 1–140 µg/m3 (average: 23 µg/m3), respectively. A slightly higher, but not significant, prevalence of reported eye- and throat-related symptoms occurred among the exposed workers than among the referents. A significantly increased risk of at least one ocular symptom was attributed to trichloramine exposure above the median (20 µg/m3). Lung function (FVC and FEV1) was in the normal range according to the Swedish reference materials, and no significant change in lung function before and after shift could be established between the groups. Average FENO values were in the normal range in both groups, but the difference in the values between the exposed workers and referents showed a significant increase after shift. Hourly registered PEF values during the day of the investigation did not show any unusual individual variability. In conclusion, the increased risk of developing at least one ocular symptom at personal trichloramine concentrations over 20 µg/m3 combined with an increase in the difference in FENO during the work shift of the exposed workers should not be neglected as an increased risk of respiratory inflammation in the habilitation and rehabilitation swimming pool environment.

0159 Relation between work-related silica exposure in foundries and cardiovascular diseases

Background Work-related exposure to silica is a health hazard worldwide causing i.e. silicosis. Some studies have also presented elevated cardiovascular disease mortality in relation to silica exposure. However, few studies focus on these diagnoses and there is lack of studies accessing morbidity. The aim of this study is to examine the morbidity and mortality of different cardiovascular diseases among Swedish silica-exposed foundry workers. Methods Measurement database, consisting of historical and present measurements (1968–2006) of respirable silica exposure, are matched against job categories, the different foundries and 4 time periods (1968–1979, 1980–1989, 1990–1999, 2000–2006) using mixed model. The cohort morbidity and mortality data were matched against registries from the Swedish National Board of Health and Welfare. SPSS and STATA were used for statistical analysis, with STATA stratified for age, gender and year. Results Cardiovascular disease (SMR 141, 95% CI 126–157) and stroke mortality (SMR 161, 95% CI 118–214) showed significant elevation. Myocardial infarction showed statistically significant reduction (SMR 73, 95% CI 60–89). Results of morbidity show significant elevation of stroke (SIR 134, 95% CI 120–150). Mean age at the time of first morbidity is 60–64 years. Conclusions This study focused on the relation between silica exposure and cardiovascular disease morbidity and mortality. Our results suggest a relation with statistically significant SMRs and SIRs, and morbidity in stroke at a younger age than the general population. Cardiovascular disease is a major cause of death worldwide, and we find a need for further examination with more extensive mapping of confounders and medical history.

Respiratory and Ocular Symptoms Among Employees at Swedish Indoor Swimming Pools

Background: This study investigated trichloramine exposure and prevalence of respiratory and ocular symptoms among Swedish indoor swimming pool workers. Methods: Questionnaires were distributed to pool workers and referents. Lung function and fraction of exhaled nitric oxide (FeNO) were measured before and after work. Exposure to trichloramine and trihalomethanes was measured over work shifts. Results: The mean personal trichloramine exposure was 36 &mgr;g/m3. Significantly more exposed workers reported ocular and nasal symptoms. There were significant differences between groups in FeNO change following work, with exposed showing increased FeNO, which grew when analyses included only nonsmokers. Conclusions: The findings indicate that indoor swimming pool environments may have irritating effects on mucous membranes. FeNO data also indicate an inflammatory effect on central airways, but the clinical relevance is unclear. Low trichloramine levels found in this study were not associated with health effects.

Protein profiles of nasal lavage fluid from individuals with work‐related upper airway symptoms associated with moldy and damp buildings

Upper airway irritation is common among individuals working in moldy and damp buildings. The aim of this study was to investigate effects on the protein composition of the nasal lining fluid. The prevalence of symptoms in relation to work environment was examined in 37 individuals working in two damp buildings. Microbial growth was confirmed in one of the buildings. Nasal lavage fluid was collected from 29 of the exposed subjects and 13 controls, not working in a damp building. Protein profiles were investigated with a proteomic approach and evaluated by multivariate statistical models. Subjects from both workplaces reported upper airway and ocular symptoms. Based on protein profiles, symptomatic subjects in the two workplaces were discriminated from each other and separated from healthy controls. The groups differed in proteins involved in inflammation and host defense. Measurements of innate immunity proteins showed a significant increase in protein S100-A8 and decrease in SPLUNC1 in subjects from one workplace, while alpha-1-antitrypsin was elevated in subjects from the other workplace, compared with healthy controls. The results show that protein profiles in nasal lavage fluid can be used to monitor airway mucosal effects in personnel working in damp buildings and indicate that the profile may be separated when the dampness is associated with the presence of molds.