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Recently, the World Health Organization Study Group on Tobacco Product Regulation (WHO TobReg) announced a priority list of 38 toxicants among the more than 7000 chemicals found in cigarette smoke, building upon previous lists of toxicants in cigarette smoke. Here, we conducted a comprehensive study on the quantitative exposure and risk characterization of these priority toxicants in mainstream cigarette smoke listed by the WHO TobReg. The human-smoked toxicant yields estimated from spent cigarette butts of a total of 361 smokers using the part-filter method (PFM) were applied to current exposure and risk estimation for the first time. The PFM can estimate human-smoked yields of toxicants using smokers' maximum mouth-level exposure. The human-smoked yield of each toxicant was converted to systemic uptake by considering bioavailability. Risk indicators-including the incremental lifetime cancer risk (ILCR), cumulative ILCR, hazard quotient (HQ), hazard indices (HIs), and margin of exposure (MOE)-were estimated from the systemic uptake of toxicants combined with Korean exposure factors by gender and age group as well as for total smokers. It was demonstrated that cigarette smoking results in significant cancer and non-cancer health risks. A sensitivity analysis showed that the human-smoked toxicant yield is one of the most important contributors to risk level variations. Our risk estimation suggested that previous risk assessments might have ignored or underestimated the uncertainty of risk assessment. In conclusion, we assessed the risk level of the 38 toxicants on the priority list developed by the WHO TobReg and provided a Korean-specific priority list for the regulations on the emission of cigarette smoke., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Because of global warming, the quantity of naturally generated mercury (Hg) will increase, subsequently methylation of Hg existing in seawater may be enhanced, and the content of metal in marine products rise which consequently results in harm to human health. Studies of the effects of temperatures on Hg absorption have not been adequate. In this study, in order to observe the effects of temperature changes on Hg absorption, inorganic Hg or methylmercury (MeHg) was added to water tanks containing loaches. Loach survival rates decreased with rising temperatures, duration, and exposure concentrations in individuals exposed to inorganic Hg and MeHg. The MeHg-treated group died sooner than the inorganic Hg-exposed group. The total Hg and MeHg content significantly increased with temperature and time in both metal-exposed groups. The MeHg-treated group had higher metal absorption rates than inorganic Hg-treated loaches. The correlation coefficients for temperature elevation and absorption were significant in both groups. The results of this study may be used as basic data for assessing in vivo hazards from environmental changes such as climate warming.

As a national project, obtaining information on the amount of heavy metal exposure of individuals through food intake is an important basic parameter for risk assessment. This study was conducted to evaluate dietary exposure levels and various risks from mercury (Hg) in Korean foods. In total, 342 samples comprising 114 food items were collected and then cooked prior to analysis. As found by Hg analysis, the mean content of metal in the fish and shellfish group was highest among the 15 Korean food groups. The total daily amount of Hg intake from typical Korean foods was 2.40 microg/person/d. The daily amount (microg/person/d) of Hg intake from each food group was 0.155 in grains and cereals, 0.008 potatoes and starch, 0.005 sugars and sweets, 0.0093 pulses, 0.0018 nuts and seeds, 0.203 vegetables, 0.027 fruits, 0.021 meats and poultry, 0.004 eggs, 1.826 fish and shellfish, 0.022 seaweed, 0.043 milk and dairy products, 0.008 oils and fats, 0.042 beverages, and 0.023 seasonings. The fish and shellfish group contributed most to total dietary intake at 76%. For risk assessment, probable daily intake (PDI) was calculated and compared with provisional tolerable weekly intake (PTWI) of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The level of Hg intake through fish and shellfish of 0.001 mg/kg body weight bw/wk corresponded to 4.54% of the PTWI value of 0.005 mg/kg bw/wk, the safety standard for JECFA. The level of Hg intake through selected foods from the Food list for Koreans was 0.001 mg/kg bw/wk, corresponding to 5.95% of PTWI value. Therefore, overall intake was at levels below the recommended JECFA levels. The relative gender Hg hazard from Korean foods was 6.26% and 5.5% for males and females, respectively. The relative age Hg hazard from Korean foods was, 8.9% in those 3-6 yr old, 6.7% in those 7-12 yr old, 5.2% in those 13-19 yr old, 5.9% in those 20-29 yr old, 6.3% in those 30-49 yr old, 5.6% in those ages 50-64 yr, and 3.7% in the group of those over 65 yr of age. Relative regional Hg hazard from Korean foods was 6.3% in urban versus 5.5% in rural areas. Thus, the amount of Hg intake through consumption of Korean foods was found to be at a relatively safe level. These data may be thus used to establish safety standards for fish and shellfish consumption.