Heavy Metal Content Of Food And Health Risk Assessment Of Some Rural Areas In Huaihe River Basin

Objective: To understand the content of heavy metals in food and the main source in study area.To estimate the oral exposure levels and health risks of residents,and clearly human exposure pathways and the sources of heavy metals.Methods:1 According to the results of an investigation,considering basin water system and the up-downstream relations,we choose four major surveys area in the Huaihe River Basin as the research area.To select a town in each county which near the river bank and had a previous related work or exposure parameter survey and environmental monitor.Choosing three natural villages in each township and requires at least one village near the river bank.2 We consumed the most consumed food for the study according to preliminary questionnaire survey results.Referring to the actual food consumption of local residents,we acquired food samples by market purchase and acquisition to farmers.Got the food samples after mixed in certain proportion,aliquot the sample and placed in sealed bags.Number and labeled,cryopreservation in-20℃,transported to the testing organizations under-4℃,conserved in-20℃before the test.3 The food items were prepared according the relevant national standard test.Samples were digested using the method of microwave digestion.The concentrations of Cd,Pb,Cr,Cu and Zn were analyzed by inductively coupled plasma mass spectrometry.Operation blank,parallel sample detection and standard quality control material were adopted to control quality.The concentrations of heavy metals in samples expressed with wet weight.（Unit: cadmium,chromium,lead,μg/kg,copper,zinc,mg/kg）.4 The estimates of heavy metals exposed via dietary According to the food consumption acquired by preliminary work and combining with metal concentrations in the foodstuffs to estimated the dietary intakes of individuals heavy metals for residents in four counties.5 Population health risk assessment Using the basic methods and patterns of health risk assessment recommended by the EPA and Combining the results of the exposure assessment and reference dose and slope factor provided by the integrated risk information system（IRIS）of EPA to estimated the health risks of heavy metals for population through food consumption.6 Used SPSS13.0 and Excel to analysis the data,mainly used descriptive statistical methods,and results were expressed as a percentage.Results:Collected 181 food samples including staple food,fruits and vegetables,meat,eggs,etc.The mean concentrations of Cr in some foodstuffs beyond the maximum levels of contaminants in food recommended by the Ministry of Health of People’s Republic of China;Pb in many vegetable samples overstepped the recommended values;Cd and Zn exceed the recommended values in some foodstuffs.The detection rate of Cr in foodstuffs is 100%.The mean concentrations of Cr in some eggs,meat,vegetables and fruits overstepped the recommended values,the rate were 66.7%,47.8%,39.3% and 66.7%,respectively.Foodstuffs overstepped the recommended values including Chinese cabbage（209μg/kg⁹27μg/kg）,spinach（517μg/kg¹876μg/kg）,green peppers（232μg/kg⁶61μg/kg）,celery（1073μg/kg）,chicken（274μg/kg¹001μg/kg）,eggs（470μg/kg¹570μg/kg）and apple（71μg/kg ¹420μg/kg）.The detection rate of Cd in foodstuffs is higher（75.5%¹00%）in four counties;The mean concentrations of Cd in flour（26.9μg/kg³2.3μg/kg）,rice（12.5μg/kg¹26.9μg/kg）and vegetables（3.2μg/kg²28.7μg/kg）are higher than other foods;Cd in spinach of Xuyi County（Xuyi）（228.7μg/kg）are exceed the recommended values.Pb in foodstuffs of Shenqiu County（Shenqiu）had a highly detection rate（97.4%）,Xuyi and the Juye County（Juye）were 65.9% and 79.6%,respectively,Yingdong District（Yingdong）was low（12.2%）;The mean concentrations of Pb in spinach samples of Shenqiu（552.7μg/kg）,Xuyi（304.0μg/kg）and Juye（304.4μg/kg）all exceeded the recommended values,Pb in Chinese cabbage samples of Xuyi（304.1μg/kg）and Juye（198μg/kg）are also exceed.The detection rate of Cu in foodstuffs of Shenqiu and Juye were 100%,Xuyi and Yingdong were 90.9% and 85.7%,respectively;The mean concentrations of Cu in Tofu（6.7mg/kg⁷.3mg/kg）,rice（5.5mg/kg⁸.0mg/kg）and flour（3.8 mg/kg 6.6 mg/kg）are relatively highly,but all within the recommended values.The detection rate of Zn in the foodstuffs of Shenqiu and Juye are 100%,Xuyi and Yingdong are 97.7% and 89.8,respectively;The mean concentrations of Zn in Pork（22.0 55.8 mg/kg）,rice（27.4 39.5 mg/kg）,tofu（11.8 35.8 mg/kg）,flour（19.4 23.8 mg/kg）and spinach（3.8 22.3 mg/kg）is relatively high,but did not exceed the recommended values.The dietary intakes of Cr for residents in four counties is very high,Pb and Cd were all within the acceptable daily allowances（ADI）,Cu and Zn were all below the Tolerable upper intake level（UL）.The average daily intake of Cr in in four counties is 494μg/d 856 μg/d,is 2.5 to 4.3 times high as ADI and each regional differences.The dietary average daily intakes of Cd was 29.7 μg/d 55.9 μg/d,did not exceed the ADI and mainly from staple food and vegetables.The daily intake of Pb is 34.7μg/d 91.7μg/d,did not exceed the ADI.The daily intake of Cu is 4.17 mg/d 5.16 mg/d,is 2.1².6 times higher than dietary reference intakes（DRIs）recommended by Chinese Nutrition Society.The daily intake of Zn is 20.5 mg/d 28.5 mg/d,Shenqiu is slightly higher than other regions.The dietary intakes of Cr,Cd,Pb were mainly from staple food and vegetables,Cu was mainly from staple food and tofu,Zn was mainly from food,meat and tofu.The target hazard quotients（THQ）of individual heavy metal through food consumption for the residents in survey area have potential health risks.The THQ of Pb from diet in Shenqiu is 1.06;The THQ of Cu from diet in Yingdong,Shenqiu,Xuyi and Juye were 1.73,1.86,1.69 and 2.09,respectively,the THQ of Zn were 1.14,1.54,1,14 and 1,11,respectively.The Hazard index（HI）via dietary for the residents in Yingdong,Shenqiu,Xuyi and Juye were 4.61,5.59,5.35 and 5.20,respectively.The results also showed that lifetime cancer risk of Cr through food consumption was between 10^-410^-3 in four counties,Xuyi and Juye were all 1.11×10^-3,overstepped an acceptable level.Conclusion:In general,the mean concentrations of Cr in the foodstuffs of four counties are exceeded recommended values,Cd and Pb in some samples had overstepped the values.The mean concentrations of Cr in vegetables,eggs and fruit（spinach,cabbage,green peppers）of Xuyi and the Juye were all exceeds the limits;Cd in rice and vegetables on the high side,Cd in spinach of Xuyi exceeded recommended values;Pb in some parts of the spinach and cabbage far exceeds the values;Cu in tofu,rice and flour,Zn in the pork,rice,tofu,flour,and spinach were relatively high,but all below the recommended values.The dietary intakes of Cr for residents in four counties is higher than those reported in China in the literature;The daily intake of Pb and Cd did not beyond the ADI recommended by WHO;The daily intake of Cu and Zn were exceed the DRIs but below the UL recommended by Chinese Nutrition Society.The daily intake of Cd,Pb and Cr were mainly from staple food and vegetables,staple food and tofu is the chief source of Cu,staple food,meat and tofu is the main source of Zn.In four research areas,the HI of heavy metals through dietary was greater than 1.The lifetime cancer risk of Cr via the dietary consumption in Xuyi and Juye exceed the acceptable level of risk(10^-4).