Spatial-temporal variability and probabilistic health risk assessment of fluoride from lentic ecosystem, Türkiye

Thrace Region is a part of the Marmara Region of Türkiye. There are many natural and artificial stagnant water habitats in the region that are used for irrigation and drinking water supply. This study is intended to determine the spatial-temporal variability and probabilistic health risk of fluoride exposure in the water of stagnant water bodies in the Thrace region. A total of 33 stagnant water bodies were selected, and water samples were collected during the dry and wet seasons of 2021–2022. The fluoride levels were measured using a spectrophotometric method (wavelength is 588 nm). The fluoride accumulations varied from 0.16–0.64 mg/L for the natural lakes, 0.04–0.74 mg/L for the reservoirs, and 0.01–0.53 mg/L for the artificial ponds. The World Health Organization (WHO) suggested a level of fluoride in drinking water of 0.5 to 1.5 mg/L. The study area had a fluoride deficiency of less than 0.5 mg/L in natural water bodies during the wet season (87.87%) and the dry season (93.93%), which might be a potential threat to dental health. Estimation Daily Intake (EDI) and Hazard Quotient (HQ) widely used health risk assessment methods were applied to the data in the current research to describe the non-carcinogenic risk of fluoride. All the calculated hazard quotient (HQ) values, both in the dry and wet seasons and in all age groups, were recorded as below 1. Both teenagers and children living in the central part of the study area are at higher risk than infants and adults. To evaluate model uncertainty, Monte Carlo simulations were employed. The outcome of the sensitivity analysis revealed that the major risks to the health of the inhabitants are the high content of fluoride and their daily intake of water.</p

Short-term dermal exposure to tannery effluent does not cause behavioral changes in male Swiss mice

<div><p>Abstract Tannery is a highly polluting activity due to the waste generated by bovine skin processing. Although there are several studies highlighting the health issues faced by workers exposed to tannery effluent, there are no records of experiments testing the neurobehavioral effects resulting from direct contact with this pollutant. Thus, the aim of the current study is to assess the possible neurobehavioral effects of dermal exposure to tannery effluent on male Swiss mice. Animals were divided in three groups, which were subjected to the same experimental time period and conditions: effluent group - animals in direct contact with tannery effluent (for 20 days); control group - animals in contact with pure water; and dry-control group - animals not exposed to water or to tannery effluent. Neurobehavioral tests started on the 17th experimental day. Results of the elevated plus-maze test (anxiety prediction) showed no anxiogenic or anxiolytic effects, memory deficit or depressive symptoms on animals exposed to tannery effluent. Thus, the current results do not support the hypothesis that male Swiss mice dermal exposure to tannery effluents for the same time period and experimental conditions leads to neurobehavioral changes. Therefore, the herein adopted exposure protocol was not good to study the effects of dermal exposure to tannery effluent on the chosen experimental model.</p></div