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@#Introduction: Pesticides may influence the physicochemical properties of soil and the water quality parameters, which is vital in maintaining soil fertility and producing high quality crops. Objective: This study aims to determine the relationship between the concentration of pesticides, the physicochemical properties of the paddy soil samples and the water quality parameters of paddy water samples. Methods: A total of 72 soil and 72 water samples were collected in Tanjung Karang, Malaysia. The paddy soil and water were extracted using Quick, Easy, Cheap, Efficient, Rugged and Safe (QuEChERS) and solid phase extraction (SPE) techniques respectively. The concentrations of pesticides were analysed in ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The relationship of the concentration of target pesticides and the paddy soil and water physicochemical properties were studied using Spearman correlation. Results: In paddy soil, the concentration of propiconazole shows moderate positive correlation with manganese (Mn) (r = 0.587) (p≤ 0.01). Meanwhile buprofezin-total organic carbon (TOC) (r = -0.55) (p≤ 0.01), imidacloprid-cation exchange capacity (CEC) (r = -0.519) (p≤ 0.01), pymetrozine-sodium (Na) (r = -0.588) (p≤ 0.01), and trifloxystrobin-calcium (Ca) (r = 0.566) (p≤ 0.01) showed moderate negative correlation. Whereas in water, trifloxystrobin showed significant positive correlation with turbidity (r = 0.718) (p≤ 0.01) and tebuconazole showed negative correlation to dissolved oxygen (DO) (r = 0.634) (p≤ 0.01). Conclusion: The presence of pesticides in paddy field may influence the soil and water quality, thus regular monitoring of pesticides usage and nutrient management in soil is deemed important.
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Abstract@#Introduction: The electronic cigarette (EC) usage has raised public health concerns; whether its advantages to smokers as a potential smoking cessation aid have outweighed its negative health impacts among EC users. This study aims to estimate health risks associated with chemical exposures to nicotine, propylene glycol (PG) and selected Tobacco-Specific Nitrosamines (TSNAs) namely 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N’-nitrosonornicotine (NNN) in e-liquids locally-manufactured in Malaysia. Methods: The health risk assessment (HRA) was performed using established guideline by the Environmental Protection Agency (EPA). The average daily dose (ADD) and lifetime average daily dose (LADD) were calculated using previously published data on chemical concentration of selected compounds and local EC usage topography data. Next, the non-carcinogenic risk (nicotine and PG) and carcinogenic risk (NNK and NNN) were calculated and denoted as total hazard quotient (HQT) and total lifetime cancer risk (LCRT) value, respectively. Results: For non-carcinogenic risk, the mean of HQT was 78.9 which falls under “unacceptable” risk as demonstrated by HQT value of more than 1. While for carcinogenic risk, the mean of total LCRT value was 1.54E-04 which may place EC users at risk of developing cancer resulted from exposure to selected TSNAs. Conclusion: Comprehensive HRA using currently available data of local EC usage topography and chemical evaluation of Malaysian-made e-liquids have revealed that the exposure to nicotine, PG and selected TSNAs are expected to be a significant health concern for local EC users. This finding supports the local health authority to issue a stringent health policy in considering EC as a tool for smoking cessation among heavy smokers.
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@#Background: Prolonged exposure of heavy metals in the respirable particulate matter (PM10) from municipal solid waste (MSW) landfills may affect children health. Objective: To investigate the association of reported respiratory symptom with heavy metals in PM10, with heavy metals in fingernails among children residing close to MSW landfills. Methods: Two groups of children age 7 to 12 years old were involved in this cross-sectional study. Those residing within 3 km radius from a landfill were the exposed group and those residing more than 3 km radius as the unexposed group. Questionnaires adapted from American Thoracic Society were applied in the survey. Fingernails were used as biomarker. Ten heavy metals elements in PM and fingernail samples were analysed using inductively coupled plasma mass spectrometry (ICP-MS). Results: The cadmium, chromium, copper, manganese, nickel and lead concentrations in PM around the MSW landfills and residential areas exceeded the Canada and USEPA standard permissible limit. Heavy metals in fingernails (p<0.001) of exposed group were significantly higher than the unexposed group. Children with no pets have less reported respiratory symptoms. Elevated level of heavy metals in PM and fingernails were associated with high risk of reported respiratory symptoms. Conclusion: Heavy metals in PM10 and fingernails were associated with potential risk factor of respiratory health in children.
ABSTRACT
Malaysia has abundant sources of drinking water from river and groundwater. However, rapid developments have deteriorated quality of drinking water sources in Malaysia. Heavy metal studies in terms of drinking water, applications of health risk assessment and bio-monitoring in Malaysia were reviewed from 2003 to 2013. Studies on heavy metal in drinking water showed the levels are under the permissible limits as suggested by World Health Organization and Malaysian Ministry of Health. Future studies on the applications of health risk assessment are crucial in order to understand the risk of heavy metal exposure through drinking water to Malaysian population. Among the biomarkers that have been reviewed, toenail is the most useful tool to evaluate body burden of heavy metal. Toenails are easy to collect, store, transport and analysed. This review will give a clear guidance for future studies of Malaysian drinking water. In this way, it will help risk managers to minimize the exposure at optimum level as well as the government to formulate policies in safe guarding the population