Publications by authors named "Mohamad Pauzi Zakaria"

Organic pollution continues to be an important worldwide obstacle for tackling health and environmental concerns that require ongoing and prompt response. To identify the LAB content levels as molecular indicators for sewage pollution, surface sediments had obtained from the South region of Malaysia. The origins of the LABs were identified using gas chromatography-mass spectrometry (GC-MS).

View Article and Find Full Text PDF

The seasonal variation of petroleum pollution including n-alkanes in surface sediments of the Selangor River in Malaysia during all four climatic seasons was investigated using GC-MS. The concentrations of n-alkanes in the sediment samples did not significantly correlate with TOC (r = 0.34, p > 0.

View Article and Find Full Text PDF

One of the molecular chemical markers used to identify anthropogenic inputs is linear alkylbenzenes (LABs) that cause serious impacts in the bays and coastal ecosystems. The surface sediments samples collected from the East Malaysia, including Brunei bay to estimate the LABs concentration and distribution as molecular markers of anthropogenic indicators. Gas chromatography-mass spectrometry (GC-MS) was used after purification, fractionation the hydrocarbons in the sediment samples to identify the sources of LABs.

View Article and Find Full Text PDF

Pollution characteristics and associated ecological risks of PAHs in sediments from Brunei Bay, Brunei were investigated. The concentrations of ∑16 PAHs ranged from 826.7 to 2955.

View Article and Find Full Text PDF

The aim of this a pioneering research is to investigate linear alkylbenzenes (LABs) as biomarkers of sewage pollution in sediments collected from four rivers and estuaries of the south and east of Peninsular Malaysia. The sediment samples went through soxhlet extraction, two-step column chromatography purification, fractionation and gas chromatography-mass spectrometry (GC-MS) analysis. Principal component analysis (PCA) with multivariate linear regression (MLR) was used as well for source apportionment of LABs.

View Article and Find Full Text PDF
Article Synopsis
  • The study examined black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) in 42 sediment samples from different coastal areas in Peninsular Malaysia.
  • The findings showed a wide range of BC (0.02 to 0.36% dw) and PAHs (57.7 to 19,300 ng g dw) concentrations, with higher levels in developed West and South coasts compared to the cleaner East coast.
  • Diagnostic ratios suggested that PAHs varied in source; petrogenic sources were prevalent in the East coast sediments, while pyrogenic sources dominated in the West and South, with significant correlations found between PAHs, BC, and total organic carbon (TOC).
View Article and Find Full Text PDF

Barnacles are ubiquitous in coastal ecosystems of different geographical regions worldwide. This is the first study attempting to assess the suitability of barnacles as bioindicators of persistent organic pollutants (POPs) in coastal environments. Barnacles were collected from the coasts around Peninsular Malaysia and analyzed for POPs including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs).

View Article and Find Full Text PDF
Article Synopsis
  • Black Carbon (BC) impacts air quality and climate, but its emission sources in Southeast Asia are not well understood; this study analyzes BC in Malaysia to determine the contributions from biomass and fossil fuels over one year.
  • The findings indicate a roughly equal contribution from biomass burning and fossil fuels overall, with seasonal variations revealing up to 70% of BC from biomass burning during the dry spring season.
  • The study highlights the need to address and reduce vegetation fires during the dry season in SE Asia to improve air quality and mitigate climate change effects.
View Article and Find Full Text PDF
Article Synopsis
  • The study focused on developing a molecular marker approach using Linear alkylbenzenes (LABs) to assess pollution in mangrove oysters from various locations in peninsular Malaysia.
  • Oysters of the C. belcheri species were collected from rivers and an island, with LABs extracted and analyzed using GC-MS; results showed the highest concentrations in oysters from Klang.
  • The findings indicated that mangrove oysters can effectively serve as biosensors for LABs contamination, highlighting their potential role in monitoring pollution levels in aquatic environments.
View Article and Find Full Text PDF

Linear alkylbenzenes were determined in the surface sediments of Muar River and Pulau Merambong, Peninsular Malaysia. The concentrations ranged from 87.4 ng g to 188.

View Article and Find Full Text PDF

The original publication of this paper contains a mistake. The correct image of figure 2 is shown in this paper.

View Article and Find Full Text PDF

Southeast Asia has undergone rapid developments in terms of urbanization, economic and population growth. The progress in sewerage treatment infrastructure has not kept pace with such developments. The inadequacy and inefficiency of sewerage systems has prompted the release of untreated sewage into the aquatic environment of Southeast Asia causing many waterborne illnesses since surface water is utilized for recreational, agricultural and aquaculture purposes and, above all, as a source of water intake in Southeast Asia.

View Article and Find Full Text PDF

Background: Numerous studies have addressed the positive effects of organic amendments on soil and plant productivity under short-term field studies. However, to date, few studies have been conducted on the effects of organic amendment on the orchards where high nutrient bioavailability is required. This study deals with the effects of biochar and compost on soil quality, growth and yield of a replanted apple orchard in the northeast of Iran.

View Article and Find Full Text PDF

Rapid increase in industrialization and urbanization in the west coast of Peninsular Malaysia has led to the intense release of petroleum and products of petroleum into the environment. Surface sediment samples were collected from the Selangor River in the west coast of Peninsular Malaysia during four climatic seasons and analyzed for PAHs and biomarkers (hopanes). Sediments were soxhlet extracted and further purified and fractionated through first and second step column chromatography.

View Article and Find Full Text PDF

The Straits of Malacca is one of the world's busiest shipping routes where frequent oil spills occur. Rapid development in the west coast of Peninsular Malaysia is the other major source of petroleum pollution in this narrow waterway. In order to identify occurrence and origin of hydrocarbons in the Straits, mangrove oysters (Crassostrea belcheri) were collected from five sampling locations and analysed for n-alkanes and biomarkers.

View Article and Find Full Text PDF

Microplastics (<5 mm) were extracted from sediment cores collected in Japan, Thailand, Malaysia, and South Africa by density separation after hydrogen peroxide treatment to remove biofilms were and identified using FTIR. Carbonyl and vinyl indices were used to avoid counting biopolymers as plastics. Microplastics composed of variety of polymers, including polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethyleneterphthalates (PET), polyethylene-polypropylene copolymer (PEP), and polyacrylates (PAK), were identified in the sediment.

View Article and Find Full Text PDF

The distribution, sources, and human health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediment and the edible tissue of short-neck clam (Paphia undulata) from mudflat ecosystem in the west coast of Malaysia were investigated. The concentrations of ∑ PAHs varied from 347.05 to 6207.

View Article and Find Full Text PDF
Article Synopsis
  • The study analyzed polycyclic aromatic hydrocarbons (PAHs) in sediment and short-neck clams from six mudflat areas on the west coast of Peninsular Malaysia, finding PAH concentrations to be significantly high in both samples, indicating moderate to very high pollution levels.
  • The research identified that PAHs in the studied areas primarily originated from pyrogenic sources, suggesting that human activities contribute notably to pollution, while also revealing that lower molecular weight PAHs preferentially accumulate in clams.
  • The findings support the idea of using short-neck clams as effective biomonitors for assessing the environmental health of mudflats, as they reflect the levels of toxic PAHs available in their environment.
View Article and Find Full Text PDF

In this study, we isolated two indigenous hydrocarbon-degrading bacteria from tarball found in Rhu Sepuluh beach, Terengganu, Malaysia. These bacteria were identified based on their physiological characteristic and 16S rRNA gene sequence analysis, and they showed 99% similarity with Cellulosimicrobium cellulans DSM 43879 and Acinetobacter baumannii ATCC 19606 respectively. Their hydrocarbon-degrading capabilities were tested using diesel-oil as sole carbon source.

View Article and Find Full Text PDF

Naturally-occurring and artificially-induced polyploids have been documented in various fish species but to date no comparison has been reported of the impacts of ploidy on fish biomarker responses to organic pollutants. This study describes effects of ploidy, gender, and dose on biliary fluorescent aromatic compound (FAC) concentrations, hepatic ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities in one of the most commonly cultured warm-water species, the African catfish Clarias gariepinus. Recently matured male and female diploid and triploid fish were intraperitoneally (i.

View Article and Find Full Text PDF

Polycyclic aromatic hydrocarbons (PAHs) and linear alkylbenzenes (LABs) were used as anthropogenic markers of organic chemical pollution of sediments in the Selangor River, Peninsular Malaysia. This study was conducted on sediment samples from the beginning of the estuary to the upstream river during dry and rainy seasons. The concentrations of ƩPAHs and ƩLABs ranged from 203 to 964 and from 23 to 113 ng g(-1) dry weight (dw), respectively.

View Article and Find Full Text PDF