Public health risk assessment from drinking water from vending machines in Seri Kembangan (Malaysia)

This study investigated the public health risk linked with microbial quality of drinking water from vending machines in Seri Kembangan city (Malaysia) using epidemiological and Quantitative Microbial Risk Assessment (QMRA) approaches. This study was also conducted to understand associations between reported health symptoms and daily water intake information. Following WHO guidelines on water safety, QMRA were performed was to estimate burden of disease from E. coli from water vending machines. Triplicate drinking water samples from water vending machines were collected from six sampling areas around the city, analysed for E. coli, information of health symptoms and daily water intake was obtained from 121 respondents by questionnaires. The results indicated the highest numbers of E. coli levels were found in Seri Serdang (45–68 CFU/100 mL) and Taman Pinggiran Putra (45–62 CFU/100 mL). Escherichia coli levels in drinking water samples from water vending machines obtained from Seri Serdang, Taman Pinggiran Putra, Taman Equine, Balakong and Serdang Jaya exceeded both Malaysian Drinking Water Quality and WHO Drinking Water Quality guidelines. Reported health symptoms were only significantly linked to brand which likely to be associated with regular maintenance of water vending machine. All the drinking water samples from water vending machines except from Lestari Perdana have exceeded the health based target outcomes by QMRA. Combination of epidemiology and quantitative microbial risk assessment have provided a clear understanding of public health risks and gateway for a better management of water vending machines

Mini review of mercury contamination in environment and human with an emphasis on Malaysia: status and needs

This article provides an overview of research on mercury (Hg) contamination in Malaysia and its evolution from 1979 to 2012. The objective of this paper was to review and provide an understanding of Hg exposures in the environment, humans, and food in Malaysia. Hg concentration in the environment is high in areas of West Port, Malacca Straits, Prai, and Johor because these areas receive anthropogenic metal loads brought about by industrial activities. Hg concentration in humans is related to seafood intake (dietary), environmental conditions, and different geographical locations. Hg levels in food showed higher concentration in the West coast of Peninsular Malaysia. Hg concentration is also present in the country’s tropical fruits, which is related to agrochemical and fertilizer usage. This review showed that there is an urgent need to identify Hg toxicology and bioaccumulation as well as the health effects of Hg exposure in different ecological compartments. This review aims to provide helpful recommendations for future Hg biomonitoring and research in Malaysia

Chlorinated Pool Attendance, Atopy, and the Risk of Asthma during Childhood

The pool chlorine hypothesis postulates that the rise in childhood asthma in the developed world could result at least partly from the increasing exposure of children to toxic gases and aerosols contaminating the air of indoor chlorinated pools. To further assess this hypothesis, we explored the relationships between childhood asthma, atopy, and cumulated pool attendance (CPA). We studied 341 schoolchildren 10–13 years of age who attended at a variable rate the same public pool in Brussels (trichloramine in air, 0.3–0.5 mg/m(3)). Examination of the children included a questionnaire, an exercise-induced bronchoconstriction (EIB) test, and the measurement of exhaled nitric oxide (eNO) and total and aeroallergen-specific serum IgE. CPA by children (range, 0–1,818 hr) emerged among the most consistent predictors of asthma (doctor diagnosed or screened with the EIB test) and of elevated eNO, ranking immediately after atopy and family history of asthma or hay fever. Although the risk of elevated eNO increased with CPA [odds ratio (OR) = 1.30; 95% confidence interval (CI), 1.10–1.43] independently of total or specific serum IgE, the probability of developing asthma increased with CPA only in children with serum IgE > 100 kIU/L (OR for each 100-hr increase in CPA = 1.79; 95% CI, 1.07–2.72). All these effects were dose related and most strongly linked to pool attendance before 6–7 years of age. Use of indoor chlorinated pools especially by young children interacts with atopic status to promote the development of childhood asthma. These findings further support the hypothesis implicating pool chlorine in the rise of childhood asthma in industrialized countries

Heavy metal contamination in urban surface soil of Klang district (Malaysia)

This study aimed to determine bioavailability of heavy metal concentrations (Al, Fe, Zn, Cu, Co, Cd, Pb and Cr) in 76 urban surface soil samples of Klang district (Malaysia). This study also aimed to determine health risks posed by bioavailability of heavy metals in urban soil on adults and children. For bioavailability of heavy metal concentrations, a physiologically bioavailability extraction test in vitro digestion model was used. Mean values of bioavailability heavy metal concentrations for this study were found to be the highest in Al (25.44 mg/kg) and lowest in Cr (0.10 mg/kg). Results of Spearman correlation coefficient (r) values showed significant correlations were observed for Al-Fe (r = 0.681), Cd-Co (r = 0.495), Cu-Zn (r = 0.232), Fe-Pb (r = 0.260), Fe-Zn (r = 0.239). For cluster analysis, output showed that these heavy metals could be classified into four clusters: Cluster 1 consisted of Cd, Cr, Co, and Pb; Cluster 2 consisted of Zn and Cu; Cluster 3 consisted of Fe; and Cluster 4 consisted of Al. For Clusters 1 and 2, anthropogenic sources were believed to be the sources, while for Clusters 3 and 4 the heavy metals originated from natural sources. Health risks were determined in adults and children through health risk assessment. For adults, Hazard Quotient (HQ) value was 1, indicating a non-carcinogenic risk. Meanwhile, for carcinogenic risk, heavy metal contamination in the Klang district might not pose a carcinogenic risk to adults while it may pose a carcinogenic risk to children because TR values in this study were >1.0E-04 for children. Output has identified the general health risk in the Klang district. Moreover, this study's findings will contribute to fill in the gap of knowledge on heavy metals' impacts on human health and urban development in the Klang District

Renal and Neurologic Effects of Cadmium, Lead, Mercury, and Arsenic in Children: Evidence of Early Effects and Multiple Interactions at Environmental Exposure Levels

Lead, cadmium, mercury, and arsenic are common environmental pollutants in industrialized countries, but their combined impact on children’s health is little known. We studied their effects on two main targets, the renal and dopaminergic systems, in > 800 children during a cross-sectional European survey. Control and exposed children were recruited from those living around historical nonferrous smelters in France, the Czech Republic, and Poland. Children provided blood and urine samples for the determination of the metals and sensitive renal or neurologic biomarkers. Serum concentrations of creatinine, cystatin C, and β(2)-microglobulin were negatively correlated with blood lead levels (PbB), suggesting an early renal hyperfiltration that averaged 7% in the upper quartile of PbB levels (> 55 μg/L; mean, 78.4 μg/L). The urinary excretion of retinol-binding protein, Clara cell protein, and N-acetyl-β-d-glucosaminidase was associated mainly with cadmium levels in blood or urine and with urinary mercury. All four metals influenced the dopaminergic markers serum prolactin and urinary homovanillic acid, with complex interactions brought to light. Heavy metals polluting the environment can cause subtle effects on children’s renal and dopaminergic systems without clear evidence of a threshold, which reinforces the need to control and regulate potential sources of contamination by heavy metals

Chemical terrorism: threats to water supplies

Although for practical reasons, terrorist attacks on water systems are considered less likely than on other targets, threats to drinking water cannot be ignored. A large-scale chemical sabotage of drinking water, even insufficient to cause casualties, could still have disastrous socio-economical consequences. There is therefore a need to maintain a high-level of security around water treatment and distribution facilities, especially those supplying critical infrastructures, and to develop emergency preparedness programs at both the local and national levels

Children and the environment : biomarkers of early effects in kidney and lung

The aim of the thesis was to evaluate the use of non-invasive biomarkers of early renal and respiratory effects in healthy children exposed in their environment to common contaminants such as heavy metals, ambient ozone, and the newly uncovered toxicant trichloramine. For this purpose, both current and innovative renal and respiratory biomarkers were applied to over 1200 children within the context of large environmental Belgian and European studies. With respect to the kidney, biomarkers of glomerular and tubular renal effects of lead, cadmium, mercury and arsenic were studied in 800 French, Czech and Polish children. The French children were analyzed first and compared to adults living in the same area. The tubular effects observed confirmed the hypothesis that children were more susceptible to heavy metal nephrotoxicity than adults. When all three cohorts of children were analyzed together, hyperfiltration was identified with serum creatinine and Ò2-microglobulin as an early glomerular effect of lead mainly. Tubular markers such as retinol-binding protein, Clara cell protein, and particularly the lysosomal enzyme N-acetyl-Ò-D-glucosaminidase, which also rose with mercury, were all correlated to cadmium. All metals showed subtle but significant interactive effects on both glomerular and tubular biomarkers. Concerning the effects of ambient air pollutants on the lung, exhaled nitric oxide was used as biomarker of inflammation in short-term ambient ozone panel studies conducted in 72 children attending summer camps in rural areas of Belgium, demonstrating increasing airway inflammation at levels below current quality guidelines. Further to the unsuspected discovery that exposure to chlorination derivatives, not ozone, was a main determinant of long-term increases in lung permeability, studies were conducted in 365 Belgian schoolchildren, for whom swimming was up to now a compulsory activity. Exhaled nitric oxide, immunoglobulins and pneumoproteins were anlayzed with a view to studying long-term effects of swimming in chlorinated pools, particularly with respect to inflammation and asthma. Serum pneumoprotein analysis indicated enhanced lung permeability and reduced Clara cell protein due to Clara cell loss with increasing pool attendance. The latter effect was observed in swimming babies, whose still developing lungs are particularly sensitive to toxicants. As to exhaled nitric oxide, which proved easily applicable in children and sensitive to both increasing levels of ozone and increasing chlorinated pool attendance, it demonstrated along with the use of immunoglobulin E levels that atopics were more at risk of developing asthma if they regularly attended chlorinated swimming pools. The inclusion of chlorination by-products in our studies was a direct consequence of using these objective and sensitive non-invasive biomarkers in children. Very few environmental studies had been conducted in children, none concerning swimming pools, and previously reported exposure levels to heavy metals or ozone were all several orders of magnitude higher than those studied here. In conclusion, non-invasive renal and respiratory biomarkers demonstrate fine and subtle responses of the children¡¦s still developing kidney and lung to common environmental toxicants such as heavy metals, ozone and chlorination derivatives at ambient levels, well below their recommended action levels.Thèse de doctorat en sciences biomédicales (orientation : toxicologie) (SBIM 3) -- UCL, 200