The introduction of total organic carbon (TOC) as a new organic matter index for industrial wastewater is under consideration. In this study, we investigated characteristics of organic pollutant indexes (TOC, BOD5, CODMn, CODCr) for 11 industrial categories comprising 210 industrial wastewater samples from Busan, Korea. Average organic concentrations for chemical manufacturing and food manufacturing industries are higher than that for other industries. The organic matter oxidation rates of CODCr and CODMn for TOC are 88.7% and 51.9%, respectively. Furthermore, the COD test can be underestimated for organic compounds in wastewater. The correlation between TOC and organic matter indexes was in the order of CODMn (r = 0.970) > CODCr (r = 0.956) > BOD5 (r = 0.812)(p < 0.01). In conclusion, the introduction of TOC, which has higher oxidation rate than COD and high correlation with existing organic matter indexes, is appropriate as an organic index to replace COD.

Hexabromocyclododecane (HBCDD) concentrations were investigated in surface sediments, core sediments, and oysters collected from densely concentrated oyster farms in the Geojae-Hansan Bay. HBCDD concentrations in surface sediments, core sediments, and oysters were 14.0~97.6 ng/g-dry, 0.46~59.8 ng/g-dry, and 0.53~1.32 ng/g-wet, respectively. The levels of HBCDDs in the inner bay, in an area with a high density of oyster farms, were higher than those in the outer bay. The HBCDD concentrations in the marine sediments in this study were comparable to or higher than those in industrialized and urbanized coastal areas in Korea. The HBCDD concentrations in the core sediment increased from the 5 cm layer (from the late 1990s) to the surface layer. Recent inputs to the bay may be associated with the increased use of HBCDDs in Korean farming activities. Of the HBCDD isomers, γ-HBCDD was dominant in marine sediments because it is a major isomer of commercial technical mixtures and expanded polystyrene buoys. In contrast, the oyster samples were dominated by α-HBCDD due to its higher assimilation efficiency and longer half-life relative to other isomers. A human health risk assessment for HBCDDs via oyster consumption for the Korean population was carried out, and the risk was very low.

This study investigates the elastic paving material coated on the floor surfaces of athletic facilities. The concentrations of Pb and DEHP(Di-(2-ethylhexyl)phthalate)) in 13 samples obtained from the flooring of an outdoor basketball court were analyzed. Additionally, a risk assessment for the human exposure was conducted. The average concentration of Pb was 2,357.5 mg/kg and ranged from 3.1 mg/kg to 13,465.4 mg/kg. The Pb concentration of 7 out of 13 samples exceeded the KS standard for Pb, which is 90 mg/kg. The largest contribution of DEHP was caused by phthalates, which measured an average concentration of 53,546.6 mg/kg in 13 samples. The hazard quotient (HQ) estimated from the Pb concentrations obtained from 10 samples taken from the surface of the palm after one hour of activity on the basketball court ranged from 0.0001 to 0.0600 and 0.0001 to 0.0550 for teenagers and adults, respectively. An increase in the HQ value was observed when evaluating the upper 95% concentrations, more specifically, 0.0006 to 0.4470 for teenagers and 0.0006 to 0.4090 for adults. The estimated excess cancer risk (ECR) of DEHP was 10-6 and 10-5 for the mean concentration and the upper 95% levels, respectively. These results suggest that there is an inherent health effect when exposed to the elastic paving materials of sports facilities. Therefore, it is necessary to set standards for elastic paving materials with a particular focus on indoor sports facilities where hazardous pollutants can easily accumulate due to the lack of ventilation.

Online headspace-SIFT/MS was evaluated by comparing performance with headspace-GC/MS for 20 types of VOCs. Performance evaluation was determined by comparing the linearity of the calibration curve, the detection limits, and the quantitation limits. The accuracy and precision of the two analytical methods were also compared. Online HSS-SIFT/MS possessed quantification almost equal to HSS-GC/MS. In the case of analysis accuracy and precision, inaccuracies were observed at low concentrations. However, overall, online HSS-SIFT/MS presented sufficient accuracy to determine the concentrations for that defines chemical accidents.

In recent years, the number of marine chemical accidents have increased with the quantity of hazardous and noxious substances (HNSs) transported by ships. The Korean government is developing response systems for such marine chemical accidents. Current technology for HNS monitoring includes various types of detection papers and kits, gas detectors, portable analyzers, and laboratory analytical instruments. Many of these resources are already in use by agencies responsible for marine chemical accident responses. However, most of these agencies do not use unmanned air and water vehicles (UAV and UWV) for sample collection and real-time monitoring of HNSs. In this study, we developed UAV and UWV disaster-management payloads for air and seawater samplers and real-time analyzers and evaluated these at several port locations. Finally, we make recommendations for an HNS response system, including a control center, a command ship, and UAV and UWV components, and propose a three-step of response procedures for chemical accidents. This system enables emergency response personnel to respond to chemical accidents more efficiently and with improved safety.

Hazardous air pollutants (HAPs) in the atmosphere are regulated and monitored in Korea by the Air Pollution Control Act. To manage HAPs, accurate standards, which are traceable to the International System of Units (SI), are required. Primary reference gas mixtures (PRMs) are prepared gravimetrically and their amount fractions (mole fractions) are gravimetrically determined values. However, for reactive gases such as volatile organic compounds (VOCs), the gravimetric values can be changed due to physical adsorption loss onto the internal surface of the cylinder. The loss can result in significant difference between the gravimetric and actual mole fractions, which is crucial for developing accurate PRMs especially for reactive gases. In this study, the physical adsorption loss onto the internal surface of the cylinder was evaluated for developing VOCs at 5 nmol mol-1. Suites of VOC gas mixtures containing the 18 components at 5 nmol mol-1 were gravimetrically prepared in aluminum cylinders. The potential physical adsorption loss was estimated by the cylinder-to-cylinder division method. The results showed that a significant physical adsorption loss occurred for acrylonitrile while little adsorption loss occurred for the other VOC components. The gravimetrically determined mole fraction for only acrylonitrile was corrected to account for the physical adsorption loss.

As turbidity can cause errors in measurements when absorbance photometry is used to determine the concentrations of heavy metal ions in real water samples (such as discharged water and industrially process water), fine solid particles should be removed during the sampling and/or sample preparation. However, complete removal is not always possible, and when an absorbance measurement needs to be carried out on a sample that is still turbid, a proper compensation method should be applied. In this short communication, accuracy was improved by means of a simple two-wavelength photometric method when absorbance was used to determine the concentrations of metal ions in samples of turbid water. The absorbance error decreased from 62.4~488% to 5.13~20.3% after the compensation method was applied.