Numerical simulation of benzene transport in shoreline groundwater affected by tides under different conditions

● An approach for assessing the transport of benzene on the beach was proposed. ● The behavior of benzene in the subsurface of the beach was impacted by tide. ● Tidal amplitude influenced the travel speed and the benzene biodegradation. ● Hydraulic conductivity had the impact on plume residence time and biodegradation. ● Plume dispersed and concentration decreased due to high longitudinal dispersivity. The release and transport of benzene in coastal aquifers were investigated in the present study. Numerical simulations were implemented using the SEAM3D, coupled with GMS, to study the behavior of benzene in the subsurface of tidally influenced beaches. The transport and fate of the benzene plume were simulated, considering advection, dispersion, sorption, biodegradation, and dissolution on the beach. Different tide amplitudes, aquifer characteristics, and pollutant release locations were studied. It was found that the tide amplitude, hydraulic conductivity, and longitudinal dispersivity were the primary factors affecting the fate and transport of benzene. The tidal amplitude influenced the transport speed and percentage of biodegradation of benzene plume in the beach. A high tidal range reduced the spreading area and enhanced the rate of benzene biodegradation. Hydraulic conductivity had an impact on plume residence time and the percentage of contaminant biodegradation. Lower hydraulic conductivity induced longer residence time in each beach portion and a higher percentage of biodegradation on the beach. The plume dispersed and the concentration decreased due to high longitudinal dispersivity. The results can be used to support future risk assessment and management for the shorelines impacted by spill and leaking accidents. Modeling the heterogeneous beach aquifer subjected to tides can also be further explored in the future study.     

Association between long-term occupational noise exposure and obesity

Noise exposure has been linked to several health outcomes including obesity. This cross-sectional study examined the association between occupational noise exposure and body mass index as a measure of general obesity in 913 textile workers (totally from nine factories) in Yazd city, Iran, from winter to summer of 2018. The sound pressure level (dBA) at each working station was measured by a calibrated sound level meter. The long-term noise exposure score of each worker (as dBA.year) was calculated by multiplying the working history in each unit to its corresponding noise level. Models were adjusted for personal, behavioral, environmental, and family history factors. In total, 81.05% (n?=?740) of the participants were exposed to noise levels higher than 85 dBA. The direct association was found for the fully adjusted model (β?=?0.002; 95% CI: 0.001: 0.004). For the model with past year noise exposure, a 10.6% increase in odds was observed for each 5 dBA increase in noise exposure (95% CI: 1.005: 1.216). We found a 0.1% increase in the odds of being overweight in mixed-gender analysis (95% CI: 1.001:1.002) for each 5 dBA.year in the fully adjusted model. Occupational noise exposure should be regarded as a risk factor for cardiometabolic outcomes in industrial workers.