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The aim of this study was to determine the occurrence of pesticide residues in bovine milk and associated health risks in human. To assess the pesticide residues, a total of 200 milk samples were analyzed using High Performance Liquid Chromatography (HPLC) with Photo Diode Array Detector (PDA).The residues of carbaryl, 4’4’ DDT and deltamethrin pesticides were found in the 27.5%, 11% and 5% milk samples, respectively. The spatial distribution of pesticide residues in milk samples indicated that carbaryl was wide spread over the entire study area. The non-significance differences in mean residual concentrations of all three pesticides in cow and buffalo milk samples were recorded. The human health risk assessment in terms of non-carcinogenic and carcinogenic health hazard was calculated based on both lower bound [LB (mean residue levels)] and upper bound [UB (95th percentile level)] limits at current levels of pesticides in bovine milk samples. The estimated average daily dietary intake (EADDI) of studied pesticides was found below the acceptable dietary intake (ADI) for both adult and children, at mean as well as 95th percentile upper bound (UB) levels. The values suggesting lower carcinogenic and non-carcinogenic health risk to adult however children are at greater health risk.Keywords: Bovine milk, carbaryl, deltamethrin
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Objective@#Assess the health risks faced by local residents, based on the results of dioxin detection in the surrounding area of a waste incineration plant in Beijing.@*Methods@#Select three representative points plant near the waste incineration plant--the people's government, Central Primary School and a community, collect 4 air and soil samples and detect their dioxin concentrations from March to December 2016, respectively, simulate people's intake through breathing, skin contact and soil intake, assess residents' lifetime cancer risk according to epidemiological studies.@*Results@#The daily average concentration in air at three test points were 0.15, 0.17, 0.19 pg/m3, and 12.5, 20.2, 6.1 ng/kg in soil. At three representative sites, residents' lifetime cancer risk through breathing from 9.55×10-6, 1.08×10-5, 1.21×10-5 in the people's government, Central Primary School and a community, while through skin contact were 3.40×10-7, 5.50×10-7, 1.65×10-7, respectively. The lifetime cancer risk through soil intake range from 2.08×10-6 to 6.91×10-6. The lifetime cancer risk of eating vegetables ranges from 5.50×10-6 to 6.98×10-6. The lifetime cancer risk of eating chicken or eggs ranges from 2.72 ×10-9 to 6.30×10-9. Residents' lifetime cancer risk through soil intake, eating vegetables and eating chicken or eggs ranges from 2.08×10-6 to 6.30×10-9.@*Conclusion@#Under all exposures, the life time risk of cancer for residents around the waste incineration is under the upper end of the range of acceptability(10-4).
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Objective To estimate the radiation dose and cancer risk of thyroid for children who underwent head CT or chest CT scans.Methods The parameters used in the CT scans were accessed from the DICOM files through PACS used DCMTK software, then the thyroid radiation dose was estimated with the CT-Expo(C) software and the cancer risk induced by CT scan was projected based on BEIR Ⅱ model combined with the Chinese cancer incidence and lifetime table in 2008.Results CT parameters used for different ages were roughly the same, the thyroid equivalent dose for head CT ranged from 1.2-2.0 mGy, the highest thyroid cancer risk occurs for newborn girls, about 9.6/100 thousand population;while for chest CT the thyroid equivalent dose ranged from 8.1 to 38.0 mGy, the highest thyroid cancer risk was also for newborn girls, about 244.7/100 thousand population.The radiation dose and cancer risk for thyroid decreased with the increased age.Conclusions The radiation dose for thyroid from chest CT was relatively higher than head CT, especially for newborn babies;therefore more protection should be given to the thyroid and other radio-sensitive organs during CT scanning.
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The γ radiation exposure due to radioactivity concentration of 40K, 238U and 232Th in soil samples from 250 different locations from 40 communities in the oil – producing region of Nigeria was carried out. The radioactivity concentrations of these radionuclides were used to determine the absorbed dose, annual effective dose equivalent, the health hazard indices and cancer risk using standard analytical methods. The range of values for the absorbed dose are 6.97 nGyh-1 to 33.29 nGyh-1, annual effective dose equivalent (outdoor) are 8.55 μSvy-1 to 40.83 μSvy-1 and (indoor) are 34.19 μSvy-1 to 163.36 μSvy-1. The external hazard index ranges from 0.038 to 0.174 while the internal health hazard index is from 0.045 to 0.191. The cancer risk obtained for the communities ranges from 0.030 x 10-3 to 0.143 x 10-3. All these values are below the standard limits when compared to the world permissible United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR) values for such environment. This shows that the exploration and exportation of crude oil in Nigeria did not pose a radioactive health hazard to the oil producing communities.
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Radioactivity measurements were carried out in and around Warri Refining and Petrochemical Company in the Niger Delta region of Nigeria for the naturally occurring radionuclides of 40K, 238U and 232Th. The values were used to determine the excess lifetime cancer risk (ELCR) and the radiation health hazard indices. Results show that the ELCR value within the company premises is 0.12×10-3 while the highest value was 0.17×10-3 from Ugborikoko Community. The internal health hazard index ranged from 0.02 – to 0.64 and the external health hazard index ranged from 0.02 – 0.33. All these values were less than the world permissible standards. It could be concluded that the potential carcinogenic risk from gamma radiation doses to the population in and around the refining and petrochemical company is low.