Search

In this study, levels and sources of aliphatic hydrocarbons and hopanes in surface sediments collected from rivers and estuaries of Peninsular Malaysia were assessed. The concentrations of total n-...

This study determined the levels of Cd, Cu, Fe, Ni, and Zn in the soft tissues and shells of barnacles (Balanus sp.) collected from the Kuala Juru, Sebatu, Sg. Ayam and Kg. Pasir Puteh, Peninsular Malaysia, obtained in 2008. The metal concentrations (μg/g dry weight) in the soft tissues of Balanus sp. received from four sites in Peninsular Malaysia ranged from 2.93-4.17 for Cd, 20.2-92.5 for Cu, 480-1193 for Fe, 6.40-18.0 for Ni, and 224-414 for Zn. Based on the present data, the trace metal bioavailability’s to the Balanus in all the populations, especially in a known polluted site at Kg. Pasir Puteh is low. Overall, this preliminary baseline data can be used for regular ecological monitoring for the effective management of the coastal area in Malaysia.

Due to extremely high rates of evaporation and low precipitation in the Persian Gulf, discharges from desalination plants (DPs) can lead to ecological stresses by increasing water temperatures, salinities, and heavy metal concentrations, as well as decreasing dissolved oxygen levels. We discuss the potential ecological impacts of DPs on marine organisms and propose mitigating measures to reduce the problems induced by DPs discharges. The daily capacity of DPs in the Persian Gulf exceeds 11 million m3 per day, which is approximately half of global daily freshwater production; multistage flash distillation (MSF) is the dominant desalination process. Results from field and laboratory studies indicate that there are potentially serious and chronic threats to marine communities following exposure to DP discharges, especially within the zoobenthos, echinodermata, seagrasses, and coral reefs. DP discharges can lead to decreases in sensitive species, plankton abundance, hard substrate epifauna, and growth rates of seagrasses. However, the broad applicability of any one of these impacts is currently hard to scale because of the limited number of studies that have been conducted to assess the ecological impacts of DP discharge on Persian Gulf organisms. Even so, available data suggest that appropriately sited, designed, and operated DPs combined with current developments in impingement and entrainment reduction technology can mitigate many of the negative environmental impacts of DPs.

The objective of this commentary is to promote the use of bivalves as biomonitors, which is a part of the continual efforts of the International Mussel Watch. This commentary is an additional discussion on “Bivalve mollusks in metal pollution studies: From bioaccumulation to biomonitoring” by Zuykov et al., published in Chemosphere 93, 201–208. The present discussion can serve as a platform for further insights to provide new thoughts and novel ideas on how to make better use of bivalves in biomonitoring studies. The certainty of better and more extensive applications of mollusks in environmental monitoring in the future is almost confirmed but more studies are urgently needed. With all the reported studies using bivalves as biomonitors of heavy metal pollution, the effectiveness of using Mussel Watch is beyond any reasonable doubts. The challenge is the development of more accurate methodologies for of heavy metal data interpretation, and the precision of the biomonitoring studies using bivalves as biomonitors, whether in coastal or freshwater ecosystems. Lastly, inclusion of human health risk assessment of heavy metals in commercial bivalves would make the research papers of high public interest.

The aim of this paper is to determine and discuss the Concentrations of Copper (Cu) in the different soft tissues of Perna viridis and surface sediments collected from western and eastern parts of Johore Singapore Causeway. In general, it is found that the different tissues of eastern mussel populations were found to have significant (p < 0.05) higher Cu levels than those in the western mussel populations. This indicated higher Cu bioavailability in the eastern part of causeway than that in the western part. The geochemical fractions (except for oxidizable-organic fraction) showed significant (p < 0.05) higher Cu levels in the eastern sediments than those in the western part of the causeway. This indicated higher Cu contamination in the eastern part of causeway than that in the western part. With consistent scientific reports of high metal levels in the eastern part of causeway between 2015-2018, it is predicted that there is a plausible constant source of anthropogenic metal contamination at the eastern part of the causeway beyond 2020 should there is no drastic effective control of the anthropogenic activities.

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 These nitrate levels in the south western part ranged from mg L while those in the north western part ranged from to mg L These nitrate levels in these intertidal waters were much lower than those found for urban drainages to mg L of Peninsular Malaysia Overall the mean values for the nitrate concentrations mg L follow Urban drainages gt north western intertidal gt south western intertidal The results showed the occurrence of nitrate contaminatin 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

This study aimed to investigate the ecological risk assessment of Khamir, Tiyab, and Jagin estuaries and the impact of anthropogenic activities on these ecosystems during a one-year study period (April 2015 to March 2016) using trace metals as pollution indices. The sediment samples were collected from nine sampling stations, following a gradient of contamination from the industrial wastewater and shrimp farming effluents to the less impacted stations. Pollution indices (i.e. PERI and PLI) were applied to ascertain the sediment quality. Based on pollution indices, the overall pattern of environmental quality status demonstrated that industrial sewage and shrimp farming effluents are major sources of pollution in the Khamir and Tiyab estuaries, respectively. The sediments in the most stations in studied coastal ecosystems of Iran posed moderate or considerable ecological risk. Results from this study showed that Zn, Pb, Cu, and Cd were mostly derived from anthropogenic activities such as domestic sewage and industrial effluents. Also, the findings of this study revealed that the pollution indices are suitable for evaluating the environmental situation of coastal ecosystems and the separation of areas with less impacted by human activities from areas affected by these activities and could be used as a robust management tool for monitoring programs in coastal areas. Altogether, these findings could be useful in providing more effective and targeted strategies of development better management practices for coastal areas.

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 distribution and sources of PAHs in jinga shrimp (Metapenaeus affinis), and human health risks due to consumption was evaluated in collected samples from the Musa Bay, Persian Gulf. The total concentration of PAHs (∑16PAHs) ranged from 10 to 144 μg kg−1 dry weight, indicating low to moderate level of pollution. The PAHs were dominated by three- (41%) and two-ring (38%) compounds. Source identification analyses indicated the PAH pollution mostly originated from petroleum inputs. A preliminary evaluation of human health risk using chronic daily intake, hazard index, benzo[a]pyrene-equivalent (BaPeq) concentration (PEC) as well as the incremental life cancer risk and non-cancer risk assessment suggest low potential health risk for consumers of the Metapenaeus affinis. However, the results indicate minimal risks associated with the intake of PAHs via shrimp consumption, but long-term monitoring is required to evaluate the changes in ecological and human health impacts of contaminants in the region. Main finding PAHs in Metapenaeus affinis from Musa bay, which influenced by anthropogenic activities were low to moderate level of pollution. Human health risk indicates low potential health risk for consumers.

The pre sent study analyzed the relationships of two different biological assemblages (diatom and macroinvertebrate) when they are used to characterize a set of stations (from reference stations to impacted stations) within the Shahrood River. In particular, we examined the issue of concordance among these assemblages and the physicochemical parameters detected, using both multivariate and multimetric methods. In addition, the trophic diatom index and Hilsenhoff family-level biotic index for macroinvertebrate assemblages were used to evaluate the ecological status of the Shahrood River. Diatom and macroinvertebrate assemblages in the Shahrood River differed significantly between reference and impacted stations. ANOSIM showed a significant difference in the composition and abundance of diatoms and macroinvertebrates among reference, influence and impact stations, especially between reference and impact stations. Results of CCA ordination showed that benthic diatoms and macroinvertebrate assemblages were mainly affected by DO, TSS, NO3 −, PO4 3− concentrations and heavy metals such as Zn and Cd. Biotic indices for the Shahrood River suggested a water quality category of “fair” with fairly substantial organic pollution for the impacted stations. Finally, our results suggest that an appropriate management and restoration policy needs to be implemented for the Shahrood basin.

This study evaluates the impact of anthropogenic activities on the Shahrood River using water physico-chemical variables and macroinvertebrates data sets obtained over a period of 12 months between February 2012 and February 2013 at 8 sampling sites. Biotic indices i.e. FBI and BMWP based on macroinvertebrates and physico-chemical indices (MPI, HPI and NSF-WQI) were employed to evaluate the water quality status in connection with natural- and human-induced pressures. Based on physico-chemical indices, water quality was categorized as low polluted level and it is suitable for drinking purposes. The water quality based on biotic indices was related to the anthropic activities; a clear deterioration of the water quality was observed from upstream to downstream sites. The water quality along the river changed from very good (class I; reference sites) to good (class II; midstream sites) and turned into moderate (class III) and poor (class IV) quality (downstream sites). These findings indicate that biotic indices are more powerful indicators in assessing water quality than physico-chemical indices. Allocapnia, Glossosoma and Hesperoperla were exclusively related to least disturbed sites, and Naididae, Orthocladiinae and Ecdyonurus were found in sites showing notable degradation. Our results recommended that the use of macroinvertebrates could be employed as a cost-effective tool for biomonitoring and controlling of polluted riverine ecosystems in the Middle East. Finally, the results from this study may be useful not only for developing countries, but also for any organization struggling to use macroinvertebrate based indices with restricted financial resources and knowledge.