Browsing by Author "Scheepers, P.T.J."

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    Assessment of exposure of gas station attendants in Sri Lanka to benzene, toluene and xylenes.
    (Amsterdam, Elsevier, 2019) Scheepers, P.T.J.; de Werdt, L.; van Dael, M.; Anzion, R.; Vanoirbeek, J.; Duca, R.C.; Creta, M.; Godderis, L.; Warnakulasuriya, D.T.D.; Devanarayana, N.M.
    ABSTRACT:Exposure to benzene, toluene and p-, m-, o-xylene (BTX) was studied in 29 gas station attendants and 16 office workers in Sri Lanka. The aim of this study was to assess the exposure level and identify potential exposure mitigating measures. Pre- and post-shift samples of end-exhaled air were collected and analysed for BTX on a thermal desorption gas chromatography mass spectrometry system (TD-GC-MS). Urine was collected at the same timepoints and analysed for a metabolite of benzene, S-phenyl mercapturic acid (SPMA), using liquid chromatography-mass spectrometry (LC-MS). Environmental exposure was measured by personal air sampling and analysed by gas chromatography flame ionization detection (GC-FID). Median (range) breathing zone air concentrations were 609 (65.1-1960) μg/m3 for benzene and 746 (<5.0-2770) μg/m3 for toluene. Taking into account long working hours, 28% of the measured exposures exceeded the ACGIH threshold limit value (TLV) for an 8-h time-weighted average of 1.6 mg/m3 for benzene. Xylene isomers were not detected. End-exhaled air concentrations were significantly increased for gas station attendants compared to office workers (p < 0.005). The difference was 1-3-fold in pre-shift and 2-5-fold in post-shift samples. The increase from pre-to post-shift amounted to 5-15-fold (p < 0.005). Pre-shift BTX concentrations in end-exhaled air were higher in smokers compared to non-smokers (p < 0.01). Exposure due to self-reported fuel spills was related to enhanced exhaled BTX (p < 0.05). The same was found for sleeping at the location of the gas station between two work-shifts. Benzene in end-exhaled air was moderately associated with benzene in the breathing zone (r = 0.422; p < 0.001). Median creatinine-corrected S-phenyl mercapturic acid (SPMA) was similar in pre- and post-shift (2.40 and 3.02 μg/g) in gas station attendants but increased in office workers (from 0.55 to 1.07 μg/g). In conclusion, working as a gas station attendant leads to inhalation exposure and occasional skin exposure to BTX. Smoking was identified as the most important co-exposure. Besides taking preventive measure to reduce exposure, the reduction of working hours to 40 h per week is expected to decrease benzene levels below the current TLV.
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    Heart rate variability among gas station attendants exposed to benzene, toluene, and xylenes (BTX) in Sri Lanka
    (Springer Nature., 2021) Warnakulasuriya, T.; Medagoda, K.; Kottahachchi, D.; Luke, D.; Wadasinghe, D.; de Silva, D.; Ariyawansha, J.; Rathnayaka, P.; Dissanayaka, T.; Fernando, S.; Devanarayana, N.M.; Scheepers, P.T.J.
    Introduction: Benzene, toluene, and xylenes (BTX) exposure among gas station attendants in Sri Lanka is high. Cardiovascular morbidity and mortality are reported to be higher among those exposed to BTX. A hypothesis is based on alterations in the autonomic nervous system, especially disruption of autonomic regulation of the heart. Autonomic regulation of cardiac functions can be assessed by short-term heart rate variability (HRV), which measures the fluctuations in the interval between sequential sinus heartbeats. Objective: To determine whether BTX exposure affects the heart rate variability (HRV) among gas station attendants. Methods: Forty-nine gas station attendants from the Gampaha district of Sri Lanka, aged between 19 and 65 years, were recruited for the study. Age and gender-matched controls (n = 46) without occupational exposure to fuel were used as controls. Ethical approval for the study was granted by the Ethics Review Committee of the Faculty of Medicine, University of Kelaniya, Sri Lanka. Informed written consent was obtained from each participant. Demographic data were collected, and a physical examination was performed before the HRV assessment. We measured SDNN, RMSSD, pNN50, HF, LF, and LF: HF ratio as HRV indices. Pre- and post-shift samples of end-exhaled air were collected and analyzed for BTX using a thermal desorption gas chromatography–mass spectrometry system (TD-GC-MS) among 24 gas station attendants and 14 controls. As a proxy of shift exposure, we calculated the increase from pre-shift (as a baseline) to postshift and reported this as ‘delta’. Results and discussion: For gas station attendants (n = 24) median pre-/post-shift exhaled air concentrations (ng/L) were: benzene 10.47/ 19.00; toluene 10.41/21.86; m/p-xylene 1.63/2.14; o-xylene 0.93/1.42. For controls (n = 14) these values were 9.40/11.05, 3.19/3.91, 1.23/ 1.43 and 0.47/0.47. The heart rate variability (HRV) analysis showed significantly higher SDNN and SD2 among the gas station attendants (n = 49) than controls (n = 46) (Mann Whitney U = 842.00, p = 0.034 and Mann Whitney U = 843.50, p = 0.035, respectively). RMSSD, pNN50, Total power, HF, and SD1 among gas station attendants negatively correlated at a significant level with the mean increment in exposure to BTX (p\0.05).Conclusions: Exposure to BTX alters the HRV indices, indicating an effect on autonomic cardiac regulation. Funding: University of Kelaniya research grant: RP/03/04/03/01/ 2017, Foreign Award 2017 of the Dutch Occupational Hygiene Society (NVvA).