Farzaneh Mohammadi

Background: Microplastics (MPs) exposure can affect humans in various ways, with tap water being one of the potential sources. Microplastics can absorb other pollutants and pose risks to both humans and the environment. Objectives: The aim of this study was to investigate the presence of MPs in tap water from the drinking water distribution system of Isfahan, Iran, and to determine the exposure to MPs from drinking tap water. Methods: Samples were collected from different points in the drinking water distribution system of Isfahan, Iran. Samples were prepared for analysis through filtration and chemical digestion. The MPs were counted using a scanning electron microscope (SEM), and the composition of MPs was analyzed using a micro-Raman spectrometer. Results: The concentration of MPs in tap water was found to be 287.0 ± 65.9 MPs/l. MPs ≤ 10 µm were the predominant sizes, and fibers were the predominant shape. Polyethylene terephthalate, polyethylene, and polypropylene were the most frequently identified MPs, respectively. Conclusions: Considering that the Iranian population consumes 7 - 15 liters of water daily for drinking and cooking, it is estimated that the average intake of MPs through cooking and drinking water is 2009 - 43,051 particles per day.

Background: Welding fumes (WFs) contain heavy metals that can induce oxidative stress and health issues in welders. This review investigated the relationship between oxidative stress biomarkers and trace metals in welders’ bodily fluids. Methods: Online databases such as Scopus, PubMed, Web of Science, Science Direct, EMBASE, and Google Scholar were reviewed, with a specific emphasis on the effects of metal fume exposure during welding. Specific keywords such as "welding fumes", "metal fumes", "antioxidant enzymes", "biomarkers", and similar terms were employed to search for articles published between 2004 and 2023. After the evaluation of article titles and abstracts, this study reviewed a total of 19 articles. Results: Studies suggest that welders experience oxidative stress due to changes in trace metals in their body fluids, affecting antioxidant enzymes and oxidative stress biomarkers. Elevated heavy metals in welders’ biological samples lead to oxidative stress and inflammation, even at low levels. Certain metals in blood and urine, such as lead (Pb), manganese (Mn), iron (Fe), chromium (Cr), and cadmium (Cd), positively correlate with serum superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels. There is also a significant positive correlation between serum/EBC MDA and blood/urine Pb, Mn, Cd, Cr, and Fe, indicating cellular damage, lipid peroxidation, and reduced antioxidant capacity. Additionally, welders may experience more DNA damage compared to non-welders. Conclusion: Exposure to WFs significantly altered oxidative stress biomarkers in bodily fluids, underscoring the importance of the relationship between oxidative stress and trace metal imbalances in WF-related injuries. These factors could serve as valuable biomarkers for monitoring workers exposed to WFs.

Nail salons offer a developing and diverse occupation for many women, especially the new generation. Due to the increasing apprehension surrounding heavy metals in dust caused by filing nails containing dried nail polish, the present study was designed aimed to health risk assessment of heavy metals in breathing zone of nail salon technicians (NSTs). This is a cross-sectional study that was conducted in NSTs. The concentration of Cadmium (Cd), Lead (Pb), Nickel (Ni), Chromium (Cr) and Manganese (Mn)in breathing zone of 20 NSTs was determined using ICP-OES. The metal concentrations were in the following order: Mn > Pb > Ni > Cr > Cd with corresponding arithmetic mean values of0.008, 0.0023, 0.0021, 0.001 and 0.0006 mg m^-3, respectively, which are exceeded the recommended levels stated in the indoor air guidelines. The average lifetime carcinogenic risk (LCR) for Cr, Cd, Ni and Pb was calculated 0.0084, 0.00054, 0.00026 and 1.44 E - 05, respectively. The LCR values of all metals (except Pb) exceeded the acceptable level set by the USEPA. The mean of Hazard quotients (HQ) for Mn, Cd, Cr, Ni and Pb were calculated to be23.7, 4.74, 2.19, 0.51 and 0.0.24, respectively. The sensitivity analysis showed that, the exposure frequency (EF) for Cr and Ni had the strong effects on generation of both LCR and HQ. Furthermore, the concentrations of Mn, Cd and Pb had strong impacts on the HQ generation and the concentration of Cd and Pb had main effects on LCR generation. To effectively reduce pollutant concentration, it is recommended to install a ventilation system near nail salon work tables and conduct continuous monitoring and quality control of nail products.

In this study, the occurrence and environmental risks related to triclosan (TCS) in the two wastewater treatment plants (WWTPs) were investigated in Isfahan, Iran. Influent and effluent samples were collected and analyzed by dispersive liquid–liquid microextraction (DLLME)–GC–MS method with derivatization. Moreover, the risk of TCS exposure was conducted for aquatic organisms (algae, crustaceans, and fishes) and humans (males and females). TCS mean concentrations in influent and effluent of WWTPs were in the range of 3.70–52.99 and 0.83–1.09 μg/L, respectively. There were also no differences in the quantity of TCS and physicochemical parameters among the two WWTPs. The mean risk quotient (RQ) for TCS was higher than 1 (in algae) with dilution factors (DFs) equal to 1 in WWTP1. Moreover, the RQ value was higher than 1 for humans based on the reference dose of MDH (RFDMDH) in WWTP1. Furthermore, TCS concentration in wastewater effluent was the influential factor in varying the risk of TCS exposure. The results of the present study showed the risk of TCS exposure from the discharge of effluent of WWTP1 was higher than WWTP2. Moreover, the results of this study may be suitable for promoting WWTP processes to completely remove micropollutants.