Pyrethroid insecticides are known to be relatively safe for mammals and are widely used indoors. However, the safety of pyrethroids in humans remains controversial, and there are insufficient systematic comparative analyses of studies showing conflicting results. In this study, six studies on the effect of permethrin, a representative pyrethroid, on the human body were compared, and the factors responsible for the differing results were examined. Each study was analyzed based on five criteria: experimental method, test subject, type of chemical substance used in the experiment, concentration of the chemical substance, and exposure time of the chemical substance. The cytotoxicity and genotoxicity of permethrin showed significant differences depending on the experimental method, test subject, type of chemical, and the cell donors used. Thus, this study could contribute to the systematic analysis of existing studies on the human hazards of pyrethroids, to generate a more balanced consensus on their safety in humans.

The research scope of microplastics in aqueous environment has been expanding from investigation of their presence in oceanic water to the analysis of their distribution and behavior in freshwater. However, research in aqueous environment is limited because the lack of standardized evaluation techniques has resulted in the use of various unrelated analysis methods, thus making it difficult to compare data on microplastic contamination and distribution. Given their known oceanic distribution, a survey on the occurrence of microplastic contamination and behavior in the freshwater environment needs to be conducted using a precise and accurate standard analytical method. Such a method would facilitate a systematic and uniform approach to domestic and international safety management and to the development of improvement plans needed to mitigate microplastic contamination. In this study, we have summarized the technologies recently applied for microplastic analysis and for the investigation of microplastic occurrence in the freshwater environment. We have also presented a review on the analysis and evaluation of microplastic contamination in the future.

This study focuses on the feasibility of using a passive sampling device (PWSD) in marine environment. To evaluate this availability, PWSDs were deployed at seven sampling sites in Jinhae Bay for eight weeks. Four sites were in the open sea, and three sites were located in a semi-closed inner bay. To account for the adsorption losses caused by turbulence and biofouling during the sampling period, a performance reference compound (PRC) with a triolein adsorbent was spiked into a semipermeable membrane device (SPMD). The PRC recoveries were 40~78%, and the sampling rates were 2.2~7.9 L/day, as calculated using the SPMD Water Concentration Estimator v5-1 provided by the U.S. Geological Survey. The concentrations of polychlorinated biphenyls (PCBs) in PWSD were highly correlated (r = 0.962, p < 0.01) with those in the bivalves (Mytilus edulis) that were collected from the same sites where the PWSDs were deployed. However, the distribution patterns of the PCB homologues were slightly different between the PWSD and bivalves. Particles remaining in the gut of the bivalves may affect the relatively higher-molecular-weight PCBs (hexa- and hepta-). PWSD-converted PCB concentrations calculated using the SPMD Water Concentration Estimator v5-1 in the PWSDs were also highly correlated (r = 0.839, p < 0.01) with the average PCB concentrations in the seawater samples that were collected from the PWSD locations on the PWSD deployment and retrieval days. The results of principle component analysis and cluster analysis revealed different distribution patterns of the PCB homologues in the PWSDs, bivalves, and seawater.

Recently, microplastics have been reported to cause increasing harm to human health through marine environmental pollution. Because microplastics are small plastic particles having a size of <5 mm, they cannot be filtered from sewage treatment facilities and, thus, are introduced into the oceans and rivers, ultimately reaching the food chain. Synthetic fibers is the primary source of recently occurring microplastic pollution. In this study, the most commonly used polyester fiber was selected, and paper, liquid, and solid detergents were used for microplastic analysis and detergent comparison. The shapes of the fibers and detergents were confirmed through optical microscope (OM). After washing, the samples were sieved through a mesh filter (47 mm), and characterized by through fourier transform infrared spectroscopy (FT-IR) with microscope. Many fine plastics were generated in laundry using solid and paper detergents, whereas fewer microplastics were generated using liquid detergents.

A pot experiment was conducted to evaluate the effect of organic matter addition to paddy soil on the solubility of arsenic (As), iron (Fe), and manganese (Mn) in soil and on As uptake by rice. Organic matter (rice straw, cattle manure, fowls manure, and swine liquid manure), except for rice hull and rice bran (the highest C:N ratio) had no effect on As release from the soil until the middle of the growth period of rice. However, As concentration in soil solution after that time was relatively high for all treatments. This result was probably attributable to the organic matter induced reductive dissolution of Fe (hydr)oxides combined with As in soil. As concentration in soil solutions from rice hull, rice bran, and cattle manure treatments was about four times higher than that of the control, since the panicle formation stage and the As concentration in brown rice from the treatments was 0.68-0.82 mg kg-1, which was about two times higher than that of the control. The As content in brown rice from swine liquid manure (the lowest C:N ratio) treatment was 0.33-0.36 mg kg-1, similar to the control. Our study indicates that some organic matter addition to paddy soil with high As concentration could cause As release from the soil and consequently elevate its concentrations in rice grain. We recommend swine liquid manure among the studied organic matter to be added to paddy soil, where As concentration is high.

The purpose of this study was to document groundwater quality in Chungcheongnam-do. Samples were taken from Taean, Dangjin, Seocheon, Boryeong, Seosan, and Nonsan areas, and 48 water quality variables were analyzed in relation to applicable standards, including the amounts of naturally occurring radioactive materials(U and Rn). The results from testing 179 locations indicated that 128 were suitable and 51 were of unacceptable quality, in terms of drinking water quality standards. The nonconformity rate for nitrate nitrogen was 47.0%, while that for total coliforms was 24.2%. Heavy metals-such as Pb, Hg, Cd, and Cr-were detected in low concentrations at all points. Analysis of naturally occurring radioactive materials showed that U concentrations were within the water quality standard (0.03 mg/L) at all points. Rn concentrations were low in NW ‌ﾠregions such as Taean, Dangjin, Seocheon, and Boryeong, where Proterozoic sedimentary rocks were distributed, but its concentrations in the Seosan and Nonsan areas, where granite rocks were widely distributed, required closer investigation, and it was found that the alternative maximum contaminant level (148 Bq/L) was exceeded in granite soils which originated from the Mesozoic Era.

Zincon is widely used as a colorimetric reagent for determining the concentrations of heavy metals in aqueous solutions. Copper and zinc are often found in the same aqueous sample and zincon can be used to determine the concentration of both ions at different reaction pH conditions (e.g., pH 5 and 9). Reportedly, zincon forms a precipitate under acidic conditions, which may decrease the precision and accuracy of metal ion determination. In this communication, a novel sequential analysis technique for the determination of copper and zinc is reported. The precipitation problem was eliminated at a pH of 9, and the concentration of zinc ions was successfully determined by treating a copper-zinc binary mixture with zincon, and masking and demasking reagents. The concentration of copper ions was determined by treating the same copper-zinc solution with only zincon. The accuracy of the concentrations of copper and zinc ions determined using the proposed sequential analysis technique was ± 13%.

Unlike water quality, air quality is difficult to assess since pollutants are discharged and diffused via various paths. For this reason, when establishing an air management policy, complex modeling is performed to predict future environmental changes. To accurately predict air quality and suggest an appropriate pollutant management policy, the number of pollutants generated by each emission source and the number of pollutant emissions is calculated herein, and the contribution of pollutants by emission source is determined. In this respect, atmospheric modeling is being used as an important tool. However, because this modeling technique represents the problematic pollutant, it is most important to ensure the reliability of the input data to derive an accurate modeling result. In 2017, an integrated environmental management system was introduced in which the management of discharge facilities, which were applied for each medium (water quality, air, waste, etc.), was integrated and managed at the plant level. In addition, through the emission impact analysis, it is now possible to establish customized permit emission limits for each plant site by considering the effect on the surroundings and set up receptor for quantifying the concentration of additional pollutants in the emission facility. The purpose of this study is to compare domestic and foreign air pollutant emission impact analysis methods and air quality prediction models to propose development directions for future air pollutant emission impact analysis