Trihalomethanes In Air Research Articles

Are workers on board vessels involved with chemicals from treated ballast water sufficiently protected? – A decadal perspective and risk assessment

Ballast Water Managements Systems (BWMS) installed on vessels may use Active Substances (AS) to inactivate organisms. This paper provides new insights in the global issue of noxious Disinfection By-Products (DBP) produced with primarily oxidant-based BWMS, and the risk assessment for workers, including port State control officers, while performing tasks on a vessel that involve exposure to treated ballast water. The Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection – Ballast Water Working Group (GESAMP-BWWG) plays a role in the certification process of BWMS that make use of AS evaluating potential negative effects. All BWMS that passed GESAMP-BWWG Final Approval until mid 2019 were analyzed providing an overview of chemicals in the treated ballast water before and after neutralization. The ballast tank cleaning scenario, the sampling scenario, and the ballast tank inspection scenario all showed elevated human health risks using the Derived Minimal Effect Levels approach. The most critical exposure occurs in the ballast tank cleaning scenario through the inhalation of volatile DBP, such as tribromomethane. This substance may cause acute effects such as headache, dizziness and also has carcinogenic properties. The two risk reducing options available in the GESAMP-BWWG Tier 2 calculations were compared, one being mitigation measures such as protective gloves and coveralls, the other option is taking into account a time correction factor. The results showed that the trihalomethanes in air are most problematic, however, there is a possibility that the calculated values may be overestimated as generally worst case assumptions were used.

An analytical method for the analysis of trihalomethanes in ambient air using solid-phase microextraction gas chromatography-mass spectrometry: An application to indoor swimming pool complexes.

A simple method for the collection and analysis of the four brominated and chlorinated trihalomethanes (THMs) in air samples is described. Ambient air samples were collected in pre-prepared glass vials, with THM analysis performed using solid-phase microextraction gas chromatography-mass spectrometry, where the need for chemical reagents is minimized. Analytical parameters, including oven temperature program, solvent volume, incubation time, vial agitation, extraction time and temperature, as well as desorption time and temperature, were evaluated to ensure optimal method performance. The developed method allows for point-in-time quantification (compared to an average concentration measured over extended periods of time), with detection limits between 0.7to2.6µg/m3 . Excellent linearity (r2 >0.99), repeatability (3%to11% RSD), and reproducibility (3%to 16% RSD) were demonstrated over a concentration range from 2 to 5000µg/m3 . The method was validated for the analysis of THMs in indoor swimming pool air and was used to investigate the occurrence of THMs in the air above 15 indoor swimming pools. This is the first study to report the occurrence of THMs in swimming pool air in Australia, and concentrations higher than those previously reported in other countries were measured.

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

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.

DBPs in a chlorinated indoor swimming pool: occurrences and modeling

Swimming pool water contains higher chlorine residual and is maintained at a higher temperature than tap water. It constitutes environments with high levels of disinfection byproducts (DBPs) in water and air due to continuous disinfection and constant organic loading from the bathers. Exposure to DBPs is inevitable for any bather or trainer while such exposure can have cancer and non-cancer risks to humans. In this study, DBPs in tap water (S1) and water and air from a chlorinated indoor swimming pool before (S2) and after swimming (S3) were measured. Trihalomethanes (THMs) in S2 and S3 were 3.0–6.8 and 4.0–10.3 times the THMs in S1, respectively; and haloacetic acids (HAAs) in S2 and S3 were 2.3–4.3 and 2.5–5.5 times the HAAs in S1, respectively. THMs in air before swimming (S2-A) and after swimming (S3-A) were 60.4 and 77.5 μg/m 3 , respectively. Models were developed for predicting dissolved organic carbon, THMs and HAAs in swimming pool. The models showed good to excellent performance (R 2 = 0.70–0.87). The model validation studies showed moderate to good performance ( r = 0.73–0.83). The models might be useful in predicting DBPs9 exposure in swimming pools.

Predicting bromide incorporation in a chlorinated indoor swimming pool.

The water in and air above swimming pools often contain high levels of disinfection byproducts (DBPs) due to chemical reactions between chlorine- or bromine-based disinfectants and organic/inorganic matter in the source water and released from swimmers. Exposure to these DBPs, though inevitable, can pose health threats to humans. In this study, DBPs in tap water (S1), and water from a chlorinated indoor swimming pool before (S2) and after swimming (S3) were measured. The brominated species constituted the majority of DBPs formed in S1, S2, and S3. Trihalomethanes (THMs) in S3 was 6.9 (range 2.9-11.1) and 1.4 (range 0.52-2.9) times those in S1 and S2, respectively; and the haloacetic acids (HAAs) in S3 was 4.2 (range 2.5-7.5) and 1.2 (range 0.6-2.6) times those in S1 and S2, respectively. The mean THMs in air above the swimming pool before (S2-A) and after swimming (S3-A) were 72.2 and 93.0μg/m(3), respectively, and their ranges were 36.3-105.8 and 44.1-133.6μg/m(3), respectively. The average percentages of bromide incorporation (BI) into THMs in S1, S2, and S3 were 3.0, 9.3, and 10.6%, respectively; and the BI into HAAs in S1, S2, and S3 were 6.6, 12.0, and 12.2%, respectively. Several models were trained for predicting the BI into THMs and HAAs. The results indicate that additional information is required to develop predictive models for BI in swimming pools.

The influence of physicochemical properties on the internal dose of trihalomethanes in humans following a controlled showering exposure

Although disinfection of domestic water supply is crucial for protecting public health from waterborne diseases, this process forms potentially harmful by-products, such as trihalomethanes (THMs). We evaluated the influence of physicochemical properties of four THMs (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) on the internal dose after showering. One hundred volunteers showered for 10 min in a controlled setting with fixed water flow, air flow, and temperature. We measured THMs in shower water, shower air, bathroom air, and blood samples collected at various time intervals. The geometric mean (GM) for total THM concentration in shower water was 96.2 μg/l. The GM of total THM in air increased from 5.8 μg/m(3) pre shower to 351 μg/m(3) during showering. Similarly, the GM of total-blood THM concentration increased from 16.5 ng/l pre shower to 299 ng/l at 10 min post shower. THM levels were significantly correlated between different matrices (e.g. dibromochloromethane levels) in water and air (r=0.941); blood and water (r=0.845); and blood and air (r=0.831). The slopes of best-fit lines for THM levels in water vs air and blood vs air increased with increasing partition coefficient of water/air and blood/air. The slope of the correlation plot of THM levels in water vs air decreased in a linear (r=0.995) fashion with increasing Henry's law constant. The physicochemical properties (volatility, partition coefficients, and Henry's law constant) are useful parameters for predicting THM movement between matrices and understanding THM exposure during showering.

Pooling Data on Pools: Genotoxicity of Chemicals in Indoor Swimming Pools

Disinfection by-products (DBPs) form in swimming pool water from reactions between disinfectants such as chlorine and organic matter such as sweat, skin cells, and urine. A new study described in a set of three articles provides the first comprehensive characterization of DBPs in an indoor pool environment and offers initial evidence of cellular-level effects of these chemicals in swimmers in an indoor chlorinated pool [EHP 118(11):1523–1530; Richardson et al.; EHP 118(11):1531–1537, Kogevinas et al.; EHP 118(11):1538–1544, Font-Ribera et al.]. The authors assessed short-term changes in 49 healthy adults after they swam for 40 minutes in a public indoor chlorinated pool. They observed increases in two biomarkers of genotoxicity relative to the concentration of brominated trihalomethanes (THMs) in exhaled breath, which were used as a proxy of the swimmers’ total DBP exposures. Those biomarkers were micronuclei in blood lymphocytes (which have been associated with cancer risk in healthy subjects) and urine mutagenicity (a biomarker of exposure to genotoxic agents). The team also took detailed measurements of THMs in air around the pool and in exhaled breath of the swimmers before and after swimming. The investigators measured several biomarkers of respiratory effects after swimming and found changes in only one—a slight increase in serum CC16, which suggests an increase in lung epithelium permeability. However, they found no evidence that DBP exposure affected lung function. The research team identified more than 100 DBPs in the water of the chlorinated pool as well as another indoor pool disinfected with bromine. Some of these compounds had never been reported previously in swimming pool water and/or chlorinated drinking water. In vitro assays showed the swimming pool water was mutagenic at levels similar to that of drinking water but was more cytotoxic (could kill cells at a lower concentration) than drinking water. The researchers acknowledge the need for further research on a variety of swimming pools under various conditions of maintenance and use as well as more complete evaluations of the uptake and potential effects of the compounds present in pool water. They also note the importance of timing in the collection of biological samples—a parameter for which there was no precedent, given the lack of previous studies of this type with swimmers. Above all, they emphasize that positive health effects of swimming can be maintained by minimizing pool levels of DBPs.