Academic literature on the topic 'Target hazard quotients'

Contamination of methylmercury (MeHg) in aquatic products has been a wide spread health concern. The objective of this study is to determine total mercury (THg) and MeHg concentrations in different species of aquatic products from major offshore farms in China, and to assess health impacts from consumption. Results showed that the concentrations of THg and MeHg ranged 5.6–328.4 ng/g (wet weight) and 4.3–303.6 ng/g (wet weight) in aquatic products, respectively, and were very variable among species and origin sources. Target hazard quotient (THQ) suggested that MeHg exposure via consumption posed high health risks to children aged 2–7 and higher income families. Residents above the age of 13 and with low income have relatively lower health risk of MeHg exposure. Health impacts on heart attacks and newborns’ IQ from MeHg exposure were evaluated using dose-response relationships. Results showed that mother’s consumption of aquatic products (at 6 ounce per day) may cause a loss of 0.38 IQ points for newborns. For non-pregnant, consumption of aquatic products may cause an increase rate of mortality and morbidity of heart attacks at 10.59 and 78.45 per 100,000 persons, respectively. The negative health impact of consuming seawater fish was higher than freshwater fish.

碩士<br>台北醫學院<br>公共衛生學研究所<br>86<br>Polychlorinated Biphenyls (PCBs) and Metals in river fish and aquatic product s in Taiwan were analyzed. Exposure to PCBs and metals by ingesting aquatic pr oducts were studied and human health risk (including cancer and non-cancer ris k) evaluated .The risk-based concentration (RBC) of different pollutants and a cceptable consumption amount of river fish and aquatic products were calculate d .The muscle PCBs concentration of Tilapia and Mugil cephalus from downstream Tan-Shui River were 3.852 and 6.582 ppb. If one consumes these fish from Tan- Shui river，the lifetime cancer risk from PCBs intake were 2.15×10-5 and 3.67 ×10-5 estimated by the highest fish consumption amount, presented higher then acceptable risk (10-6). The RBC for PCBs estimated by the highest consumption amount of fish was only 0.179 ppb , much lower than the actual PCBs concentra tions measured. The acceptable calculated consumption of the Tilapia and Mugil cephalus were 5.33 and 3.12 g/day, much lower than average fish consumption o f 60.75 g/day estimated by the questionnaire. When non-cancer risk was estimat ed by the highest fish consumption, the Target Hazard Quotients (THQ) for AC 1 254 intake from Tilapia and Mugil cephalus from Tan-Shui River are 0.72 and 0. 92. The content of arsenic in fish、shrimp、clam and oyster bought from market were 0.055、0.099、0.054 and 0.143 ppm. Assuming inorganic arsenic accounts f or 10% of all arsenic in seafood and cancer risk estimated by the highest fish consumption, the lifetime cancer risk for arsenic from consuming fish、shrimp 、clam and oyster are 6.00×10-6、1.25×10-6、7.63×10-7 and 1.36×10-6 respec tively. All aquatic products except clam in the study presented higher then ac ceptable risk (10-6). The RBC for arsenic estimated by the highest consumption of fish、shrimp and oyster are 9、79 and 105 ng/g respectively, were lower th an actual arsenic concentration measured. The acceptable consumption for aquat ic products estimated by the actual arsenic concentration of fish、shrimp、cla m and oyster measured are 19.11、10.67、19.66 and 7.36 g/day respectively, als o lower than actual consumption estimated by the questionnaire in the study.Th e content of copper、zinc、lead、cadium and mercury in oyster bought from mark et were 20、44.2、0.011、0.056 ppm and 1.04 ppb respectively on a wet weight b asis. These metals concentration were higher than fishes、shrimp and clam. The THQ for different metals intake by consuming aquatic products were all below 1.