Dietary exposure to organochlorine pesticide residues of the Hong Kong adult population from a total diet study.

Dietary exposure of the Hong Kong adult population to organochlorine pesticide (OCP) residues was estimated using a total diet study (TDS) approach. OCPs listed under the Stockholm Convention as persistent organic pollutants (POPs) including, aldrin, dieldrin, chlordane, chlordecone, dichlorodiphenyltricholroethane (DDT), endosulfan, endrin, heptachlor, hexachlorobenzene (HCB), α-hexachlorocyclohexanes (HCH), ß-HCH, lindane, mirex, pentachlorobenzene and toxaphene, were studied. Out of 600 composite samples, 55% contained one or more OCP residues at detectable levels. The most commonly detected OCP was DDT (32% of all composite samples), followed by HCB (30%) and endosulfan (22%). The lower- and upper-bound mean exposure estimates of OCP residues ranged from 0% to 0.5% and were 0.1-8.4% of their respective health-based guidance values (HBGVs). The lower- and upper-bound 95th percentile exposure estimates ranged from 0% to 1.2% and were 0.1-13.6% of their respective HBGVs. This indicated that dietary exposures to the OCP residues analysed would be unlikely to pose unacceptable health risks to Hong Kong adults.

Dietary exposures to eight metallic contaminants of the Hong Kong adult population from a total diet study.

Dietary exposures to eight metallic contaminants, aluminium (Al), antimony (Sb), cadmium (Cd), lead (Pb), methylmercury (MeHg), nickel (Ni), tin (Sn) and vanadium (V), of the Hong Kong adult population were estimated using the total diet study (TDS) approach. The estimated mean exposures of Al (0.60 mg kg(-1) bw week(-1)), Sb (0.016-0.039 µg kg(-1) bw day(-1)), Cd (8.3 µg kg(-1) bw month(-1)), Pb (0.21 µg kg(-1) bw day(-1)), MeHg (0.74 µg kg(-1) bw week(-1)), Ni (3.1 µg kg(-1) bw day(-1)), Sn (0.029-0.031 mg kg(-1) bw week(-1)) and V (0.13 µg kg(-1) bw day(-1)) were well below the relevant health-based guidance values (HBGVs) where available. However, dietary exposures to MeHg of women aged 20-49 years (child-bearing age) accounted for 150% of the provisional tolerable weekly intake (PTWI) and to Al and Cd of some high consumers were found exceeding or approaching the HBGVs. The major food contributors of MeHg were fish and seafood (90%), of Al were non-alcoholic beverages including tea (33%), and of Cd were vegetables (36%). MeHg exposure during pregnancy was a public health concern in Hong Kong due to potential health risks to the foetus. Results suggest that there is a need to continue monitoring the exposures to metallic contaminants, especially Al, Cd and MeHg, of the Hong Kong population.

Quantitative risk-benefit analysis of fish consumption for women of child-bearing age in Hong Kong.

Maternal fish consumption is associated with both risks from methylmercury (MeHg) and beneficial effects from omega-3 fatty acids to the developing foetal brain. This paper assessed the dietary exposure to MeHg of women of child-bearing age (20-49 years) in Hong Kong, and conducted risk-benefit analysis in terms of the effects in children's intelligent quotient (IQ) based on local data and the quantitative method derived by the expert consultation of FAO/WHO. Results showed that average and high consumers consume 450 and 1500 g of fish (including seafood) per week, respectively. About 11% of women of child-bearing age had a dietary exposure to MeHg exceeding the PTWI of 1.6 µg kg(-1) bw. In pregnant women MeHg intake may pose health risks to the developing foetuses. For average consumers, eating any of the 19 types of the most commonly consumed fish and seafood during pregnancy would result in 0.79-5.7 IQ points gain by their children. For high consumers, if they only ate tuna during pregnancy, it would cause 2.3 IQ points reduction in their children. The results indicated that for pregnant women the benefit outweighed the risk associated with eating fish if they consume different varieties of fish in moderation.

Dietary exposure of the Hong Kong adult population to polybrominated diphenyl ethers (PBDEs): results of the first Hong Kong Total Diet Study.

Polybrominated diphenyl ethers (PBDEs) are a group of industrial chemicals that are persistent and can bioaccumulate. In the first Hong Kong Total Diet Study, the dietary exposure of Hong Kong adults to PBDEs was estimated to assess the associated health risks. Food samples, which represented the Hong Kong people's diet, were collected and prepared in table-ready form for analysis. Concentrations of PBDEs were determined in 142 composite samples. The dietary exposures were estimated by combining the analytical results with the local food consumption data of the adults. The mean and 95th percentile of dietary PBDEs exposures of the Hong Kong people were 1.34 and 2.90 ng kg(-1) body weight day(-1), respectively. The main dietary source of PBDEs was "fish and seafood and their products", which contributed 27.3% of the total exposure, followed by "meat, poultry and game and their products" (20.7%), "cereals and their products" (15.9%), and "fats and oils" (15.9%). The large margins of exposure (MOE) (>2.5) calculated following the European Food Safety Authority (EFSA) approach for four important congeners, BDE-47, BDE-99, BDE-153 and BDE-209, indicate that the estimated dietary exposures are unlikely to be a significant health concern.

Ethyl carbamate in fermented foods and beverages: dietary exposure of the Hong Kong population in 2007-2008.

To evaluate the potential public health risk of ethyl carbamate (EC), EC exposure from fermented foods and beverages for Hong Kong population was estimated. In 276 samples analysed, EC was detected (limit of detection (LOD) at 0.4 µg kg(-1)) in 202 samples (73%), with higher levels in fermented red bean curd (150-650 µg kg(-1)) and yellow wine (140-390 µg kg(-1)), while low or non-detected (ND) in preserved vegetables (ND-10 µg kg(-1)) and fermented tea (ND-15 µg kg(-1)). The estimated dietary exposure from all fermented foods and beverages was 8.27 ng kg(-1) bw day(-1), while exposure excluding alcoholic beverages was 5.42 ng kg(-1) bw day(-1), with calculated margins of exposure (MOEs) at 3.6 × 10(4) and 5.5 × 10(4) respectively. The risk of adverse health effects was low for the average population but higher (MOE of 10(3)) for high consumers of alcoholic beverages especially habitual drinkers of alcoholic types with high EC contents.

Dietary exposure of secondary school students in Hong Kong to polybrominated diphenyl ethers from foods of animal origin.

This paper reports levels of polybrominated diphenyl ethers (PBDEs) in a wide range of foods of animal origin and estimates their dietary exposure for secondary school students in Hong Kong, China. Dietary exposure to PBDEs was estimated using local food consumption data obtained from secondary school students in 2000 and the concentrations of PBDEs in food samples taken from local market in 2008. The PBDE levels on a fresh weight basis for fish ranged from 13 to 6600 pg g(-1), for seafood and seafood products ranged from 15 to 1200 pg g(-1), for meat and meat products ranged from 23 to 3500 pg g(-1), for poultry ranged from 68 to 670 pg g(-1), for eggs ranged from 280 to 800 pg g(-1), and for dairy products ranged from 12 to 480 pg g(-1). The dietary exposures of secondary school students for the average and high consumers were estimated to be 2.6 and 6.4 ng kg(-1) body weight day(-1), respectively. According to the Joint FAO/WHO Expert Committee on Food Additives (JECFA), for the more toxic PBDE congeners, adverse effects would be unlikely to occur in laboratory animals at doses of less than approximately 100 microg kg(-1) body weight day(-1). The resulting margins of exposures (38,000 for average consumers and 16,000 for high consumers) showed that the estimated dietary exposures of secondary school students were far below any adverse effect dose observed in laboratory animals and were therefore of low concern for human health.