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The current study assessed the ecological–health risks of potentially toxic arsenic (As) and antimony (Sb) in the vegetable Centella asiatica, topsoils, and mangrove sediments sampled from Peninsular Malaysia. The As concentrations ranged from 0.21 to 4.33, 0.18 to 1.83, and 1.32 to 20.8 mg/kg dry weight, for the leaves, stems, and roots of the vegetable, respectively. The ranges of Sb concentrations were 0.31–0.62, 0.12–0.35, and 0.64–1.61 mg/kg dry weight, for leaves, stems, and roots of the vegetable, respectively. The children’s target hazard quotient (THQ) values indicated no non-carcinogenic risks of As and Sb in both leaves and stems, although children’s THQ values were higher than those in adults. The calculated values of estimated weekly intake were lower than established provisional tolerable weekly intake of As and Sb for both children and adult consumers. The carcinogenic risk (CR) values of As for children’s intake of leaves and stems of vegetables showed more public concern than those of adults. The levels of Sb and As in the topsoils were generally higher (although not significantly) than those in the mangrove sediments, resulting in a higher geoaccumulation index, contamination factor and ecological risk, hazard index, THQ, and CR values. This indicated that the anthropogenic sources of Sb and As originated from the land-based activities before reaching the mangrove near the coast. The CR of As signifies a dire need for comprehensive ecological–health risks exposure studies, as dietary intake involves more than just vegetable consumption. Therefore, risk management for As and Sb in Malaysia is highly recommended. The present findings of the ecological–health risks of As and Sb based on 2010–2012 samples can be used as an important baseline for future reference and comparison.

The ecological and children’s Health Risk Assessments (HRA) of Copper (Cu) in aquatic bodies ranging from rivers, mangrove, estuaries, and offshore areas were studied using the Cited Cu Data in The Sediments (CCDITS) from 125 randomly selected papers published from 1980 to 2022. The ecological and children’s HRA were assessed in all CCDITS. Generally, local point Cu sources (8%) and lithogenic sources were the main controlling factors of Cu concentrations. The present review revealed three interesting points. First, there were 11 papers (8%) documenting Cu levels of more than 500 mg/kg dw while China was the country with the highest number (26%) of papers published between 1980 and 2022, out of 37 countries. Second, with the Cu data cited from the literature not normally distributed, the maximum Cu level was higher than all the established guidelines. However, the median Cu concentration was lower than most of the established guidelines. The median values of the geoaccumulation index (Igeo) indicated a status of ‘unpolluted‘ and ‘moderate contamination’ for the contamination factor (CF), and ‘low potential ecological risk’ for the ecological risk (ER) of Cu. However, the Cu ER could be based at present on the above mentioned 8% of the literature in the present study. Third, the calculated hazard index (HI) values were found to be below 1, indicating no potential chance of Cu non–carcinogenic effects in both adults and children, except for children’s HI values from Lake Pamvotis of Greece, and Victoria Harbor in Hong Kong. Thus, regular monitoring (every 2 years), depending upon the available resources, is recommended to assess the ecological–health risk of Cu pollution in aquatic bodies to abate the risk of Cu exposure to children’s health and avoid injurious impacts on the biota. It can be concluded that there is always a need for the mitigation and management of a Cu exposure risk assessment that can be used successfully for screening purposes to detect important

The present study investigated the antioxidant enzyme activities (AEA) of ascorbate peroxidase (APX), catalase (CAT), guaiacol peroxidase (GPX), and superoxide dismutase (SOD) as biomarkers of Cu and Pb stress by using Centella asiatica grown in an experimental hydroponic condition. The results showed (i) higher accumulations of Cu and Pb in the roots of C. asiatica than those in the leaves, (ii) synergistic effects of Cu and Pb stress at higher metal-level exposures, and (iii) Cu and Pb stress triggered the increment of APX, CAT, GPX, and SOD levels in both the leaves and roots of C. asiatica. The increment of four AEA indicated that C. asiatica underwent oxidative stress caused by the production of reactive oxygen species when the plant was exposed to Cu and Pb. In order to prevent damages caused by Cu and Pb stress, the AEA system was heightened in C. asiatica, in which APX, CAT, GPX, and SOD can be used as biomarkers of Pb and Cu stress in the plant.

Along with the growing utilization of zinc (Zn) and Zn-containing nanoparticles in various industries, Zn ecotoxicological evaluation on human food supply is necessary even though Zn is generally considered safe and rarely concentrated ecotoxicologically. This study aimed to investigate the bioaccumulation of Zn in 18 species of vegetables (seven leafy, nine fruity vegetables and one species each of tuber and legume) collected from two farming sites in the west coast of Peninsular Malaysia. A human health risk assessment (HHRA) was also conducted. In addition to HHRA based on the general population, HHRA based on each major ethnic group of the Malaysian society was also determined considering that the food consumption pattern would definitely be varied across ethnicities and age groups (children and adults). The study results showed that Zn concentrations were significantly higher (p < 0.05) in leafy vegetables than in other types of vegetables. However, the target hazard quotient (THQ) values were all found to be < 1.0. Therefore, based on the Malaysian ethnicities and age groups with their respective vegetable consumption patterns, the results indicated insignificant noncarcinogenic human health risk of Zn via oral consumption of vegetables by the Malaysian population. As a metric of measurement of HHRA, a comparison of THQ values could yield previously unreported insights into HHRA differences among the compared populations. A comparison of THQ values among the consumer groups indicated higher HHR for Chinese Malaysians and children due to their higher vegetable consumption and lower body weight, respectively. A comparison the Zn intakes of all the consumer groups with the recommended nutrient intakes indicated that the oral consumption of the vegetable species collected in this study would not result in Zn-related hazards and would not be able to fulfil the Zn dietary need of the individual consumer.

This study aimed to analyse ten trace metal concentrations in the edible part of the freshwater clam Corbicula javanica and to provide a critical assessment of the potential risks to human health through consumption of this clam as food based on well-established indices and food safety guidelines. The clams were captured from a pristine original site and transplanted to other sites with different environmental qualities. The trace metal levels in the edible total soft tissue (TST) of the clam were below those of the food safety guidelines referred to except for Pb, which exceeded the permissible limit set by the European Commission (2006) and the US Food and Drug Administration/ Center for Food Safety and Applied Nutrition); Interstate Shellfish Sanitation Conference. (USFDA/CFSAN; ISSC) (2007). The estimated daily intake (EDI) values of the clam were found to be lower than the oral reference dose and the calculated target hazard quotient (THQ) and total THQ were found to be less than 1. Therefore, in conclusion, the human health risk for consumption of TST of C. javanica at both average and high-level were insignificant regardless of the environment it was exposed to.

The intertidal and urban waters of west Peninsular Malaysia are interesting area for ecotoxicological studies because they receive wastes due to agricultural, municipal and industrial wastes along the west coast of Peninsular Malaysia. Surface water samplings were conducted from the intertidal coastal waters and from urban rivers/drainages from northern to southern parts of the west coastal areas of Peninsular Malaysia between January and April 2005. These nitrate levels in the south western part ranged from 0.33-0.56mg/L while those in the north western part ranged from 0.11 to 1.91mg/L. These nitrate levels in these intertidal waters were much lower than those found for urban drainages (0.45 to 2.27mg/L) of Peninsular Malaysia. Overall, the mean values for the nitrate concentrations (mg/L) follow: Urban drainages (1.04)>north western intertidal (0.79)>south western intertidal (0.43). The results showed the occurrence of nitrate contamination in the urban area due to human-induced activities such as domestic wastes. Albeit this study revealed no serious threat of nitrate contamination in the urban and intertidal coastal waters compared to the safety limits, continuous monitoring should be carried out on the concentrations of nitrate in the aquatic ecosystem of Peninsular Malaysia since it could be a harmful nutrient to living organisms if presented in excessive concentrations.

The concentrations of Fe and Ni were analyzed in the water spinach Ipomoea aquatica collected from 11 sampling sites (Ara Kuda (2016), Setiawan (2016), Sikamat (2013-2018) and 8 sites in Sepang area (2005-2006)) from Peninsular Malaysia. The range of Fe (mg/kg dw) in the plant samples was 155-775(15.5-77.5mg/kg ww) while the range of Ni(mg/kg dw) was 1.71-20.3(0.17-2.03 mg/kg ww). In assessing the human health risk, the target hazard quotient values for Fe and Ni in Malaysian adults are <1.00. The current results showed no non-carcinogenic risks of Fe and Ni through the consumption of I. aquatica from the 11 sites. Considering the fact that most of the samples were collected from the wild and grown in the uncontrolled drainages, the heavy metal concentrations should be closely monitored in these vegetables.

This study investigated the concentrations of Ni and Fe in 18 vegetables (12 fruit types and 6 leafy types) and their habitat topsoils collected from three farming sites in Peninsular Malaysia. The levels of Ni and Fe are all significantly (P<0.05) higher in the leafy vegetables than those in the fruit vegetables. It is found that the Ni levels in the vegetables are highly correlated with the three geochemical and non-resistant fractions of the habitat topsoils. This indicated that Ni geochemical fractions in the habitat topsoils are considered readily and potentially bioavailable to the vegetables. The Fe levels in the vegetables are highly correlated with the ‘acid-reducible’ fraction of the habitat topsoils, indicating the Fe transfer of this geochemical fraction is likely to occur to the vegetables. The positive relationships indicated the potential of edible vegetables as good biomonitors of Ni pollution in the habitat topsoils. For the health risk assessment, all the target hazard quotient values for Ni and Fe in the 18 vegetables investigated in both adult and children are all below 1.00. This indicated that there was no non-carcinogenic risk of Ni and Fe to the consumers for both adults and children.

Samplings of intertidal snails were done in January-April 2005 along the northern part of Peninsular Malaysia. Five taxa of intertidal snails (Pomacea canaliculata, Nerita lineata, Chicoreus capucinus, Thais sp. and Telescopium telescopium) were analysed for Cd, Cu, Fe, Ni, Pb and Zn. Based on the analyses of the different species, it can be concluded that 1) the highest and the lowest levels of metals in all species were Fe and Cd, respectively, which is in line with the abundance of these metals in the nature; 2) the levels of metals in the soft tissues and shells of the snails species were significantly different which were due to metal handling strategies and regulations; and 3) these metal accumulations in the soft tissues and shells shed lights on effective management of marine ecosystem in future studies.

Background:Present study focused on the relationships of Zn concentrations between Centella asiatica(leaves, stems and roots) and their habitat topsoils.Methods & Materials: For leaves, it is found that Zn levels in the leaves significantly (P< 0.05) correlated with geochemical fractions of easily, freely,leachable or exchangeable (EFLE) (R= 0.94), acid-reducible (AR) (R= 0.63), oxidisable-organic (OO) (R= 0.85), resistant (R) (R=0.79) and summation of all four fractions (SUM) (R= 0.83). For stems, it is found that Zn levels in the stems significantly (P< 0.05)correlated with AR (R= 0.73), R (R= 0.75) and SUM (R= 0.72). For roots, it is found that Zn levels in the roots significantly (P<0.05) correlated with EFLE (R= 0.88), AR (R= 0.65), OO (R= 0.86), R (R= 0.77) and SUM (R= 0.82).Conclusion: These results indicated that the three parts of C. asiatica are able to reflect the Zn concentrations in the habitat topsoils. Based on ecological risk (Er) of the habitat topsoils, all samplings sites were categorized as ‘Low potential ecological risk’ according to Hakanson classification. Based on the positive significant relationships of Zn concentrations between plant parts and geochemical fractions of their habitat topsoils, present study indicated that C. asiatica can be used as biomonitoring plant of Zn polluted topsoils.

The present study aimed to assess the effects of anthropogenic activities on the heavy metal levels in the Langat River by transplantation of Corbicula javanica. In addition, potential ecological risk indexes (PERI) of heavy metals in the surface sediments of the river were also investigated. The correlation analysis revealed that eight metals (As, Co, Cr, Fe, Mn, Ni, Pb and Zn) in total soft tissue (TST) while five metals (As, Cd, Cr, Fe and Mn) in shell have positively and significantly correlation with respective metal concentration in sediment, indicating the clams is a good biomonitor of the metal levels. Based on clustering patterns, the discharge of dam impoundment, agricultural activities and urban domestic waste were identified as three major contributors of the metals in Pangsun, Semenyih and Dusun Tua, and Kajang, respectively. Various geochemical indexes for a single metal pollutant (geoaccumulation index (I geo), enrichment factors (EF), contamination factor (C f) and ecological risk (Er)) all agreed that Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn are not likely to cause adverse effect to the river ecosystem, but As and Pb could pose a potential ecological risk to the river ecosystem. All indexes (degree of contamination (C d), combined pollution index (CPI) and PERI) showed that overall metal concentrations in the tropical river are still within safe limit. River metal pollution was investigated. Anthropogenic activities were contributors of the metal pollution. Geochemical indexes showed that metals are within the safe limit.

Kelimpahan dan kepelbagaian makroinvertebrata serta parameter air dikaji di lima sungai Lembangan Sungai Juru di utara semenanjung Malaysia; Sungai Ceruk Tok Kun (CTKR), Sungai Pasir (PR), Sungai Permatang Rawa (PRR), Sungai Kilang Ubi (KUR) dan Sungai Juru (JR). Abundance and diversity of macroinvertebrates as well as physico-chemical parameters of the water were investigated in five rivers of the Juru River Basin in northern Peninsula Malaysia; Ceruk Tok Kun River (CTKR), Pasir River (PR), Permatang Rawa River (PRR), Kilang Ubi River (KUR), and Juru River (JR).

Kajian ekologi dan molekul dijalankan terhadap serangga akuatik Chironomidae (Diptera) yang mendiami kawasan sawah padi di Stesen Kaiian Pertanian Bukit Merah (BMAES), Seberang Perai, Pulau Pinang, Malaysia. Penyiasatan terhadap taburan dan kelimpahan chironomid (Chironomidae: Diptera) menunjukkan bahawa taburan populasi larva chironomid meningkat dan menurun mengikut perubahan dinamik ekosistem sawah padi. Kepadatan tertinggi dalam musim pertama ialah 294.39m-2 dan 306.37m-2 dalam musim kedua. Penyampelan larva setiap dua minggu selama dua musim penanaman 2004/2005 menunjukkan bahawa Chironomus kiiensis adalah spesies yang paling dominan ditemui. Manakala empat lagi spesies, Polypedilum lrigonus, Tanytarsus formosanus, Tanypus punctipennis and Clinotanypus sp didapati dalam jumlah yang rendah walaupun ditemui pada sepanjang masa sawah padi dipenuhi air. An ecological and molecular study was conducted on the aquatic insect Chironomidae (Diptera) inhabiting the rice field in Bukit Merah Agricultural Research Station (BMAES), Seberang Perai, Pulau Pinang Malaysia. Investigation on the distribution and abundance of chironomid larvae (Chironomidae: Diptera) showed that the larval population fluctuated following the dynamic changes in rice field ecosystem. The maximum density in the first season was 294.39 m-2 and 306.37 m-2 in the second season. Biweekly sampling of larvae over two rice growing seasons of 2004/2005 revealed that Chironomus kinesis was the most abundant species while four other species Polypedilum trigon us, Tanytarsus formosanus, Tanypus punctipennis and Clinotanypus sp were found in low numbers although they occurred during all rice wet phases.