Occurrence of N-nitrosamines in the atmosphere and human health risk: A case study in an urban area of Chuncheon, Gangwon State, South Korea.

This study aimed to investigate the occurrence of eight nitrosamines (NAs) in particulate (PM) and gaseous phases and assess the human health risk associated with these compounds in an urban area of Chuncheon, Gangwon State, South Korea, across four sampling seasons. The findings revealed that the total concentrations of eight NAs measured during the sampling period exceeded the public health recommendation of 0.3 ng/m provided by the Norwegian Institute of Public Health, indicating a potential human health risk from NA exposures.

Use of flat-sheet membrane extraction with a sorbent interface for solvent-free determination of BTEX in water.

An analytical method for solvent-free determination of benzene, toluene, ethylbenzene, and xylenes (BTEX) in water using flat-sheet membrane extraction with a sorbent interface (MESI) coupled to GC-MS was established by optimizing the flow rates of the donor (20 ml water) and acceptor (helium) phases and extraction temperature. BTEX compounds permeated through a nonporous silicone membrane and evaporated into the acceptor phase were purged into a cryofocusing trap (-30 °C) with helium gas. Enriched compounds were thermally desorbed into a capillary gas chromatograph and detected with a mass spectrometer.

Ingestion exposure to nitrosamines in chlorinated drinking water.

Objectives: N-Nitrosodimethylamine (NDMA) is classified as a probable human carcinogen by the United States Environmental Protection Agency (US EPA) and is formed during the chlorination of municipal drinking water. In this study, selected nitrosamines were measured in chlorinated drinking water collected from Chuncheon, Kangwon-do, Republic of Korea, and a risk assessment for NDMA was conducted.

Methods: Twelve water samples were collected from 2 treatment plants and 10 household taps.

Seasonal variations in the household exposures of Korean housewives to volatile tap water disinfection by-products.

This study was conducted to compare housewives' winter and summer exposures to volatile disinfection by-products (DBPs) in chlorinated tap water. A total of 60 households were visited for this purpose: 27 in winter and 33 in summer. Each subject was given a questionnaire regarding general tap water use, household ventilation time, and activities related to water use.

Distribution and mobility of chromium, copper, and arsenic in soils collected near CCA-treated wood structures in Korea.

Chromated copper arsenate (CCA) is currently the most commonly used wood preservative in Korea. Questions, however, have been raised regarding the potential environmental impacts of metal leaching from CCA-treated wood to soil. Although a number of researchers from other countries have reported that chromium, copper, and arsenic do leach from CCA-treated wood over time, to date few field studies have been performed on those metals in soils adjacent to CCA-treated wood structures in Korea.

Effect of PCB 126 on hepatic metabolism of thyroxine and perturbations in the hypothalamic-pituitary-thyroid axis in the rat.

The objective of this research was to examine the time- and dose- dependent disturbances in the hypothalamic-pituitary-thyroid (HPT) axis of adult male rats administered a potent coplanar (non-ortho) PCB, 3,3',4,4',5-pentachlorobiphenyl (PCB 126). Adult male Sprague-Dawley rats were administered a single oral bolus dose of 0, 7.5, 75, or 275 microg PCB 126/kg bw dissolved in corn oil.

Formation of disinfection by-products in chlorinated swimming pool water.

The formation of five volatile disinfection by-products (DBPs: chloroform, bromodichloromethane, chloral hydrate, dichloroacetonitrile, and 1,1,1-trichloropropanone) by the chlorination of the materials of human origin (MHOs: hair, lotion, saliva, skin, and urine) in a swimming pool model system was examined. Chlorination reactions took place with a sufficient supply of chlorine residuals (0.84 mg Cl2/l < total chlorine < 6.