In this study, we assess the intense pollution episode of June 2013, in Riau province, Indonesia from land clearing. We relied on satellite retrievals of aerosols and Carbon monoxide (CO) due to lack of ground measurements. We used both the yearly and daily data for aerosol optical depth (AOD), fine mode fraction (FMF), aerosol absorption optical depth (AAOD) and UV aerosol index (UVAI) for characterizing variations. We found significant enhancement in aerosols and CO during the pollution episode. Compared to mean (2008-2012) June AOD of 0.40, FMF-0.39, AAOD-0.45, UVAI-1.77 and CO of 200 ppbv, June 2013 values reached 0.8, 0.573, 0.672, 1.77 and 978 ppbv respectively. Correlations of fire counts with AAOD and UVAI were stronger compared to AOD and FMF. Results from a trajectory model suggested transport of air masses from Indonesia towards Malaysia, Singapore and southern Thailand. Our results highlight satellite-based mapping and monitoring of pollution episodes in Southeast Asia.
This study assessed the economic value of health impacts of transboundary smoke haze pollution in Kuala Lumpur and adjacent areas in the state of Selangor, Malaysia. Daily inpatient data from 2005, 2006, 2008, and 2009 for 14 haze-related illnesses were collected from four hospitals. On average, there were 19 hazy days each year during which the air pollution levels were within the Lower Moderate to Hazardous categories. No seasonal variation in inpatient cases was observed. A smoke haze occurrence was associated with an increase in inpatient cases by 2.4 per 10,000 populations each year, representing an increase of 31 percent from normal days. The average annual economic loss due to the inpatient health impact of haze was valued at MYR273,000 ($91,000 USD).
Polycyclic aromatic hydrocarbons (PAHs) in soil have been recognised as a serious health and environmental issue due to their carcinogenic, mutagenic and teratogenic properties. One of the commonly employed soil remediation techniques to clean up such contamination is soil washing or solvent extraction. The main factor which governs the efficiency of this process is the solubility of PAHs in the extraction agent. Past field-scale soil washing treatments for PAH-contaminated soil have mainly employed organic solvents or water which is either toxic and costly or inefficient in removing higher molecular weight PAHs. Thus, the present article aims to provide a review and discussion of the alternative extraction agents that have been studied, including surfactants, biosurfactants, microemulsions, natural surfactants, cyclodextrins, vegetable oil and solution with solid phase particles. These extraction agents have been found to remove PAHs from soil at percentages ranging from 47 to 100% for various PAHs.
The phytotoxic risk of ambient air pollution to local vegetation was assessed in Selangor State, Malaysia. The AOT40 value was calculated by means of the continuously monitored daily maximum concentration and the local diurnal pattern of O3. Together with minor risks associated with the levels of NO2 and SO2, the study found that the monthly AOT40 values in these peri-urban sites were consistently over 1.0 ppm.h, which is well in exceedance of the given European critical level. Linking the O3 level to actual agricultural crop production in Selangor State also indicated that the extent of yield losses could have ranged from 1.6 to 5.0% (by weight) in 2000. Despite a number of uncertainties, the study showed a simple but useful methodological framework for phytotoxic risk assessment with a limited data set, which could contribute to appropriate policy discussion and countermeasures in countries under similar conditions.
In this paper, we concisely reviewed the contamination of persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) in human breast milk collected from Asian countries such as Japan, China, Philippines, Vietnam, Cambodia, India, Malaysia, and Indonesia during 1999-2003. Dioxins, PCBs, CHLs in Japanese, and DDTs in Vietnamese, Chinese, Cambodian, Malaysian, and HCHs in Chinese, Indian, and HCB in Chinese breast milk were predominant. In India, levels of dioxins and related compounds (DRCs) in the mothers living around the open dumping site were notably higher than those from the reference site and other Asian developing countries, indicating that significant pollution sources of DRCs are present in the dumping site of India and the residents there have been exposed to relatively higher levels of these contaminants possibly via bovine milk.
Polycyclic aromatic hydrocarbons (PAHs) are present in both gaseous and particulate phases. These compounds are considered to be atmospheric contaminants and are human carcinogens. Many studies have monitored atmospheric particulate and gaseous phases of PAH in Asia over the past 5 years. This work compares and discusses different sample collection, pretreatment and analytical methods. The main PAH sources are traffic exhausts (AcPy, FL, Flu, PA, Pyr, CHR, BeP) and industrial emissions (BaP, BaA, PER, BeP, COR, CYC). PAH concentrations are highest in areas of traffic, followed by the urban sites, and lowest in rural sites. Meteorological conditions, such as temperature, wind speed and humidity, strongly affect PAH concentrations at all sampling sites. This work elucidates the characteristics, sources and distribution, and the healthy impacts of atmospheric PAH species in Asia.
Concentrations of 20 trace elements were determined in muscle and liver of 34 species of marine fish collected from coastal areas of Cambodia, Indonesia, Malaysia and Thailand. Large regional difference was observed in the levels of trace elements in liver of one fish family (Carangidae): the highest mean concentration was observed in fish from the Malaysian coastal waters for V, Cr, Zn, Pb and Bi and those from the Java Sea side of Indonesia for Sn and Hg. To assess the health risk to the Southeast Asian populations from consumption of fish, intake rates of trace elements were estimated. Some marine fish showed Hg levels higher than the guideline values by U.S. Environmental Protection Agency and Joint FAO/WHO Expert Committee on Food Additives (JECFA). This suggests that consumption of these fish may be hazardous to the people.
Skin is a major by-product of the fisheries and aquaculture industries and is a valuable source of gelatin. This study examined the effect of triploidization on gelatin yield and proximate composition of the skin of African catfish (Clarias gariepinus). We further investigated the effects of two commonly used pesticides, chlorpyrifos (CPF) and butachlor (BUC), on the skin gelatin yield and amino acid composition in juvenile full-sibling diploid and triploid African catfish. In two separate experiments, diploid and triploid C. gariepinus were exposed for 21 days to graded CPF [mean measured: 10, 16, or 31 μg/L] or BUC concentrations [Mean measured: 22, 44, or 60 μg/L]. No differences in skin gelatin yield, amino acid or proximate compositions were observed between diploid and triploid control groups. None of the pesticide treatments affected the measured parameters in diploid fish. In triploids, however, gelatin yield was affected by CPF treatments while amino acid composition remained unchanged. Butachlor treatments did not alter any of the measured variables in triploid fish. To our knowledge, this study is the first to investigate changes in the skin gelatin yield and amino acid composition in any animal as a response to polyploidization and/or contaminant exposure.
Information on the biological responses of polyploid animals towards environmental contaminants is scarce. This study aimed to compare reproductive axis-related gene expressions in the brain, plasma biochemical responses, and the liver and gill histopathological alterations in diploid and triploid full-sibling juvenile African catfish (Clarias gariepinus). Fish were exposed for 96 h to one of the two waterborne phenanthrene (Phe) concentrations [mean measured (SD): 6.2 (2.4) and 76 (4.2) μg/L]. In triploids, exposure to 76 μg/L Phe increased mRNA level of fushi tarazu-factor 1 (ftz-f1). Expression of tryptophan hydroxylase2 (tph2) was also elevated in both ploidies following the exposure to 76 μg/L Phe compared to the solvent control. In triploids, 76 μg/L Phe increased plasma alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) levels compared to the other Phe-exposed group. It also elevated lactate and glucose contents relative to the other groups. In diploids, however, biochemical biomarkers did not change. Phenanthrene exposures elevated glycogen contents and the prevalence of histopathological lesions in the liver and gills of both ploidies. This study showed substantial differences between diploids and triploids on biochemical and molecular biomarker responses, but similar histopathological alterations following acute Phe exposures.
Most studies of metals exposure focus on the heavy metals. There are many other metals (the transition, alkali and alkaline earth metals in particular) in common use in electronics, defense industries, emitted via combustion and which are naturally present in the environment, that have received limited attention in terms of human exposure. We analysed samples of whole blood (172), urine (173) and drinking water (172) for antimony, beryllium, bismuth, cesium, gallium, rubidium, silver, strontium, thallium, thorium and vanadium using ICPMS. In general most metals concentrations were low and below the analytical limit of detection with some high concentrations observed. Few factors examined in regression models were shown to influence biological metals concentrations and explained little of the variation. Further study is required to establish the source of metals exposures at the high end of the ranges of concentrations measured and the potential for any adverse health impacts in children.
The ability of Pycnoporus sanguineus to adsorb heavy metals from aqueous solution was investigated in fixed-bed column studies. The experiments were conducted to study the effect of important design parameters such as column bed height, flow rate and initial concentration of solution. The breakthrough profiles were obtained in these studies. A mathematical model based on external mass transfer and pore diffusion was used for the prediction of mass transfer coefficient and effective diffusivity of metals in macro-fungi bed. Experimental breakthrough profiles were compared with the simulated breakthrough profiles obtained from the mathematical model. Bed Depth Service Time (BDST) model was used to analyse the experimental data and evaluated the performance of biosorption column. The BDST model parameters needed for the design of biosorption columns were evaluated for lead, copper and cadmium removal in the column. The columns were regenerated by eluting the metal ions using 0.1 M hydrochloric acid solution after the adsorption studies. The columns were subjected to repeated cycles of adsorption of same metal ions and desorption to evaluate the removal efficiency after adsorption-desorption.
The occurrence of tributyltin (TBT) is reported in the coastal waters of a few selected sites in Peninsular Malaysia. Water, bivalves and sediment samples collected were analysed specifically for TBT using sensitive analytical methods which involved a solvent extraction procedure with appropriate clean-up followed by graphite furnace atomic absorption spectrometric measurements. The levels of TBT in the seawater in unexposed areas were found in the range from <3.4 to 20 ng litre(-1) as compared to coastal areas with high boat and ship activities where TBT levels in seawater were generally above 30 ng litre(-1), with the highest level found at 281.8 ng litre(-1). TBT levels in the tissues of random cockle and soft-shell clam samples from local markets were found in the range from <0.5 to 3.7 ng g(-1) wet weight. The levels of TBT found in green mussel samples both from the market (23.5 ng g(-1) wet weight) and those from a mussel farm (14.2 ng g(-1) wet weight) indicate slight accumulation of TBT. In sediments, TBT levels were found ranging from <0.7 ng g(-1) dry weight in unexposed coastal sites to as high as 216.5 ng g(-1) dry weight for a site within a port area.
The study of lead exposure among workers in Selangor and the Federal Territory was carried out based on the delta-aminolevulinic acid (ALA) level in urine. Occupations which are expected to have higher lead exposure were chosen in this research. The ALA level in the workers' urine was linked to a few variables which may contribute to the lead level in the body. The result of this study showed that the ALA level of the urine of university students (0.352 +/- 0.038 mg/100 ml) < clerical staff (0.560 +/- 0.043 mg/100 ml) < traffic police (0.612 +/- 0.064 mg/100 ml) < vehicle workshop workers (0.673 +/- 0.099 mg/100 ml) < petrol kiosk workers (0.717 +/- 0.069 mg/100 ml) < bus drivers/conductors (0.850 +/- 0.055 mg/100 ml) which was similar to workers in the printing industry (0.852 +/- 0.110 mg/100 ml). The ALA levels in the urine of the exposed workers were significantly different from the control group (university students). However, results obtained from clerical staff revealed that they were also in the exposed group category. Analysis of variance showed that the exposed groups are in a population which is different from the control population. Correlation tests suggest that there is no significant connection between the ALA level in the urine and the variables tested. Furthermore, Duncan's Multiple Range Test showed no significant differences between the smoking/non smoking group, alcoholic/non-alcoholic group, race and sex (p > 0.05).
The effect of the oil-spill dispersant Corexit 9527 on egg-hatching rate of Macrobrachium rosenbergii (de Man) was studied by using an innovated flow-through bioassay technique. This bioassay method relies on the fact that M. rosenbergii fertilized eggs when detached from the mother prawn were able to hatch artificially. The flow-through system generated a stable and good water quality environment for hatching the eggs successfully. The Corexit 9527 had a pronounced effect on hatching rate of the M. rosenbergii eggs. In the control, the hatching rate of the eggs was 95.55% +/- 1.74%. However, it was reduced drastically with increasing concentrations of Corexit 9527. A 100% inhibition of egg hatchability was found when the level of Corexit 9527 was higher than 250 mg litre(-1). The EC(50) and the EC(95) values estimated by the probit method were 80.4 +/- 5.5 mg litre(-1) and 193.5 +/- 39.9 mg litre(-1) respectively (P = 0.05). The recommended safety level of Corexit 9527 for M. rosenbergii in Malaysian estuarine waters is below 40 mg litre(-1).
A study was carried out to determine the chemical composition of bulk precipitation, throughfall and stemflow in an urban forest in Kuala Lumpur, Malaysia. The mean weekly rainfall recorded during the period of study was 63.2 mm. Throughfall, stemflow and canopy interception of incident precipitation were 77.1%, 1.2% and 21.7% respectively. Bulk precipitation, througfall and stemflow were acidic, the pH recorded being 4.37, 4.71 and 4.15 respectively. In all cases the dominant ions were NO3, SO4, Cl, NH4, K, Ca and Na. Of the ions studied Ca, K, Cl, SO4, Mg and Mn showed net increases in passing through the forest canopy, while NH4, Na, NO3, Zn, H and Fe showed net retention. This study shows that the urban environment of Kuala Lumpur contributes considerable amounts of materials to the atmosphere, as reflected by the high ionic contents in bulk precipitation, throughfall and stemflow.
Persistent organochlorines in air, river water and sediment samples were analysed from eastern and southern Asia (India, Thailand, Vietnam, Malaysia, Indonesia) and Oceania (Papua New Guinea and Solomon Islands) to elucidate their geographical distribution in tropical environment. The concentrations of organochlorines in these abiotic samples collected from Taiwan, Japan and Australia were also monitored for comparison. Atmospheric and hydrospheric concentrations of HCHs (hexachlorocyclohexanes) and DDTs (DDT and its metabolites) in the tropical developing countries were apparently higher than those observed in the developed nations, suggesting extensive usage of these chemicals in the lower latitudes. CHLs (chlordane compounds) and PCBs (polychlorinated biphenyls) were also occasionally observed at higher levels in the tropics, implying that their usage area is also expanding southward. Distribution patterns of organochlorines in sediments showed smaller spatial variations on global terms, indicating that the chemicals released in the tropical environment are dispersed rapidly through air and water and retained less in sediments. The ratios of organochlorine concentrations in sediment and water phases were positively correlated with the latitude of sampling, suggesting that persistent and semivolatile compounds discharged in the tropics tend to be redistributed on a global scale.
Chemical forms of copper and lead in river water of the Linggi River Basin have been fractionated into ASV labile, moderately labile, slowly labile, and inert metal species, based on a previously proposed scheme. Free (hydrated) metal ions were identified by a potentiometric method using an ion selective electrode. Speciation results showed that the soluble copper and lead species occurred mainly in the moderately labile and slowly labile fractions. The speciation results are primarily interpreted in terms of organic interaction due to agricultural based and light industries, and urban discharges. The measured metal complexing capacity (MCC) of the samples reveals consistency of the results with the nature of the discharge. MCC correlates reasonably well with the value from the permanganate test on the river water. In general, the speciation pattern was found to be consistent with the findings of other workers.
Concentration of butyltin compounds (BTs), including tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) and total tin (SigmaSn) were determined in green mussel (Perna viridis), 10 species of muscle fish and sediment from coastal waters of Malaysia. BTs were detected in all these samples ranging from 3.6 to 900 ng/g wet wt., 3.6 to 210 ng/g wet wt., and 18 to 1400 ng/g dry wt. for mussels, fish and sediments, respectively. The concentrations of BTs in several locations of this study were comparable with the reported values from some developed countries and highest among Asian developing nations. Considerable concentration of BTs in several locations might have ecotoxicological consequences and may cause concern to human health. The parent compound TBT was found to be highest than those of its degradation compounds, DBT and MBT, suggesting recent input of TBT to the Malaysian marine environment. Significant positive correlation (Spearman rank correlation: r2=0.82, P<0.0001) was found between BTs and SigmaSn, implying considerable anthropogenic input of butyltin compounds to total tin contamination levels. Enormous boating activities may be a major source of BTs in this country, although aquaculture activities may not be ignored.
There are serious concerns over the adverse impacts of microplastics (MPs) on living organisms. The main objective of this study was to test the effects of MPs on the total length, weight, condition factor (CF), transcriptional level of antioxidant, anti and pro-apoptotic, and neurotransmitter genes, and the histopathology of the gill, liver, brain, kidney, and intestine in the larvae of zebrafish (Danio rerio). Fish were exposed to one of three levels of pristine low-density polyethylene (LDPE) fragments (5, 50, or 500 μg/L) for 10 or 20 days. No significant changes were observed in any of the selected biomarkers across MP concentrations at days 10 or 20. The expression of casp9 (caspase 9, apoptosis-related cysteine protease), casp3a (caspase 3, apoptosis-related cysteine protease a) and cat (catalase), however, were significantly lower in the larvae sampled at day 20 than day 10. We provide evidence that virgin short-term exposure to LDPE fragments has minimal impact on biomarker responses in D. rerio larvae.
Six different approaches are applied in the present study to apportion the sources of precipitation nitrogen making use of precipitation data of dissolved inorganic nitrogen (DIN, including NO3- and NH4+), dissolved organic nitrogen (DON) and δ15N signatures of DIN collected at six sampling sites in the mountain region of Southwest China. These approaches include one quantitative approach running a Bayesian isotope mixing model (SIAR model) and five qualitative approaches based on in-situ survey (ISS), ratio of NH4+/NO3- (RN), principal component analysis (PCA), canonical-correlation analysis (CCA) and stable isotope approach (SIA). Biomass burning, coal combustion and mobile exhausts in the mountain region are identified as major sources for precipitation DIN while biomass burning and volatilization sources such as animal husbandries are major ones for DON. SIAR model results suggest that mobile exhausts, biomass burning and coal combustion contributed 25.1 ± 14.0%, 26.0 ± 14.1% and 27.0 ± 12.6%, respectively, to NO3- on the regional scale. Higher contributions of both biomass burning and coal combustion appeared at rural and urban sites with a significant difference between Houba (rural) and the wetland site (p