Characterization of polycyclic aromatic hydrocarbons in atmospheric aerosols collected from selected locations in peninsular Malaysia

With rapid modernization and development of Malaysia during the recent years, atmospheric hydrocarbons have been increasing due to increase in industrialization, motorization, biomass burning and deforestation in this country. One of the most important classes of hydrocarbons is polycyclic aromatic hydrocarbon (PAHs) that has long been of interest in the field of environmental forensic. It is very important to characterize the Polycyclic Aromatic Hydrocarbons in the environment because of the known carcinogenic and mutagenic effect of theses compounds to human health especially on the endocrine system. Generally, anthropogenic PAHs are released from both pyrogenic and petrogenic sources. Particulate phase PAHs have significant contribution from the total concentration of PAHs in the atmosphere. This study specifically focuses on characteristics of this group of compounds in total suspended particulates at nine sampling stations in peninsular Malaysia. The objectives of this project are to determine the sources, distribution and concentrations of compound specific PAHs in selected locations. For this purpose, atmospheric aerosols are collected using high volume air samplers. The samples are further soxhlet extracted using high-grade dichloromethane then purified and fractionated by a two-step column chromatography. Subsequently, PAHs fraction with 3-5 benzene rings is analyzed by gas chromatography coupled with mass spectrometer (GC-MS). The results of this study revealed that concentration of PAHs ranged from 0.28 to 13.02 ng/m3 with the mean value of 2.73 ng/m3. The ratio of the sum of methylphenanthrenes to phenanthrene (MP/P) was under unity for 16 samples from the 18 samples analyzed. This result indicated that the atmospheric PAHs are from pyrogenic sources. Interestingly samples from Tanah Rata station MP/P ratio were found to be above unity that may come from petrogenic input of PAHs. Application of lower molecular weight (LMW) to higher molecular weight (HMW) PAHs proportion provided very useful supportive data to identify the origin of PAHs. The results indicated that distribution of compound specific PAHs during the sampling period are strongly controlled by dominance of higher molecular weight PAHs, which is consistent with results of MP/P ratio. The only exceptions consist of two samples from Alor Setar and Tanah Rata stations that LMW/HMW and MP/P ratios do not relate to each other, suggesting unique source of PAHs in the study area that contains both pyrogenic and petrogenic PAHs. Finally, it has concluded that the atmospheric environment of peninsular Malaysia during the period of sampling has influenced by pyrogenic sources of PAHs

Snow scavenging and phase partitioning of nitrated and oxygenated aromatic hydrocarbons in polluted and remote environments in central Europe and the European Arctic

Nitrated and oxygenated polycyclic aromatic hydrocarbons (N/OPAHs) are emitted in combustion processes and formed in polluted air. Their environmental cycling through wet deposition has hardly been studied. Fresh snow samples at urban and rural sites in central Europe, as well as surface snow from a remote site in Svalbard, were analysed for 17 NPAHs, 8 OPAHs, and 11 nitrated mono-aromatic hydrocarbons (NMAHs), of which most N/OPAHs as well as nitrocatechols, nitrosalicylic acids, and 4-nitroguaiacol are studied for the first time in precipitation. In order to better understand the scavenging mechanisms, the particulate mass fractions (θ) at 273&thinsp;K were predicted using a multi-phase gas-particle partitioning model based on polyparameter linear free energy relationships.  ∑NPAH concentrations were 1.2&ndash;17.6 and 8.8–19.1&thinsp;ng&thinsp;L&minus;1 at urban and rural sites, whereas  ∑OPAHs were 79.8&ndash;955.2 and 343.3&ndash;1757.4&thinsp;ng&thinsp;L−1 at these sites, respectively. 9,10-anthraquinone was predominant in snow aqueous and particulate phases. NPAHs were only found in the particulate phase with 9-nitroanthracene being predominant followed by 2-nitrofluoranthene. Among NMAHs, 4-nitrophenol showed the highest abundance in both phases. The levels found for nitrophenols were in the same range or lower than those reported in the 1980s and 1990s. The lowest levels of  ∑ N/OPAHs and  ∑ NMAHs were found at the remote site (3.5 and 390.5&thinsp;ng&thinsp;L&minus;1, respectively). N/OPAHs preferentially partitioned in snow particulate phase in accordance with predicted θ, whereas NMAHs were predominant in the aqueous phase, regardless of θ. It is concluded that the phase distribution of non-polar N/OPAHs in snow is determined by their gas-particle partitioning prior to snow scavenging, whereas that for polar particulate phase substances, i.e. NMAHs, is determined by an interplay between gas-particle partitioning in the aerosol and dissolution during in- or below-cloud scavenging.</p

Characterization of alkanes, hopanes, and polycyclic aromatic hydrocarbons (PAHs) in tar-balls collected from the East Coast of Peninsular Malaysia

The East Coast of Peninsular Malaysia faces the South China Sea and is vulnerable to oil pollution because of intense petroleum production activities in the area. The South China Sea is also a favored route for supertankers carrying crude oil to the Far East. Consequently, oil spills can occur, causing pollution and contamination in the surrounding areas. Residual oil spills stranded on coastal beaches usually end up as tar-balls. Elucidating the sources of tar-balls using a molecular marker approach is essential in assessing environmental impacts and perhaps settling legal liabilities for affected parties. This study utilizes a multimodal molecular marker approach through the use of diagnostic ratios of alkanes, hopanes, and polycyclic aromatic hydrocarbons (PAHs) to determine the source, distribution and weathering of tar-balls. Hopane ratios (e.g., C29/C30, and ∑C31–C35/C30 ratios) were used to identify the sources of tar-balls. The weathering effects were distinguished by using alkanes, namely the unresolved complex mixture (UCM) and low molecular weight/high molecular weight (L/H) ratios. Similarly, PAHs were also used for the determination of weathering processes undergone by the tar-balls. This multimodal molecular marker gave a very strong indication of the sources of tar-balls in this study. For example, 16 out of 17 samples originated from South East Asian Crude Oil (SEACO) with one sample from Merang, Terengganu originating from North Sea Oil (Troll). The TRME-2 sample may have come from a supertanker’s ballast water discharge. The second possibility is that the tar-ball may have been transported via oceanographic currents. All ‘weathered’ sample characterizations were based on the presence of UCM and other ratios. The multimodal molecular marker approach applied in this study has enabled us to partially understand the transport behavior of tar-balls in the marine environment and has revealed insights into the weathering process of tar-balls

Nitrated monoaromatic hydrocarbons (nitrophenols, nitrocatechols, nitrosalicylic acids) in ambient air: levels, mass size distributions and inhalation bioaccessibility

Nitrated monoaromatic hydrocarbons (NMAHs) are ubiquitous in the environment and an important part of atmospheric humic-like substances (HULIS) and brown carbon. They are ecotoxic and with underresearched toxic potential for humans. NMAHs were determined in size-segregated ambient particulate matter collected at two urban sites in central Europe, Ostrava and Kladno, Czech Republic. The average sums of 12 NMAHs (Σ12NMAH) measured in winter PM10 samples from Ostrava and Kladno were 102 and 93 ng m−3, respectively, and 8.8 ng m−3 in summer PM10 samples from Ostrava. The concentrations in winter corresponded to 6.3–7.3% and 2.6–3.1% of HULIS-C and water-soluble organic carbon (WSOC), respectively. Nitrocatechols represented 67–93%, 61–73% and 28–96% of NMAHs in PM10 samples collected in winter and summer at Ostrava and in winter at Kladno, respectively. The mass size distribution of the targeted substance classes peaked in the submicrometre size fractions (PM1), often in the PM0.5 size fraction especially in summer. The bioaccessible fraction of NMAHs was determined by leaching PM3 samples in two simulated lung fluids, Gamble’s solution and artificial lysosomal fluid (ALF). More than half of NMAH mass is found bioaccessible, almost complete for nitrosalicylic acids. The bioaccessible fraction was generally higher when using ALF (mimics the chemical environment created by macrophage activity, pH 4.5) than Gamble’s solution (pH 7.4). Bioaccessibility may be negligible for lipophilic substances (i.e. log KOW &gt; 4.5)

Oxygenated and Nitrated Polycyclic Aromatic Hydrocarbons in Ambient Air-Levels, Phase Partitioning, Mass Size Distributions, and Inhalation Bioaccessibility

Among the nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs and OPAHs) are some of the most hazardous substances to public health, mainly because of their carcinogenicity and oxidative potential. Despite these concerns, the concentrations and fate of NPAHs and OPAHs in the atmospheric environment are largely unknown. Ambient air concentrations of 18 NPAHs, 5 quinones, and 5 other OPAHs were determined at two urban and one regional background sites in central Europe. At one of the urban sites, the total (gas and particulate) concentrations of Sigma(10)OPAHs were 10.0 +/- 9.2 ng/m(3) in winter and 3.5 +/- 1.6 ng/m(3) in summer. The gradient to the regional background site exceeded 1 order of magnitude. Sigma(18)NPAH concentrations were typically 1 order of magnitude lower than OPAHs. Among OPAHs, 9-fluorenone and (9,10)-anthraquinone were the most abundant species, accompanied by benzanthrone in winter. (9,10)-Anthraquinone represented two-thirds of quinones. We found that a large fraction of the target substance particulate mass was carried by submicrometer particles. The derived inhalation bioaccessibility in the PM10 size fraction is found to be approximate to 5% of the total ambient concentration of OPAHs and up to approximate to 2% for NPAHs. For 9-fluorenone and (9,10)-anthraquinone, up to 86 and 18%, respectively, were found at the rural site. Our results indicate that water solubility could function as a limiting factor for bioaccessibility of inhaled particulate NPAHs and OPAHs, without considerable effect of surfactant lipids and proteins in the lung lining fluid

Spatial distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in green mussels (Perna viridis) from coastal areas of Peninsular Malaysia: implications for source identification of perylene

Distribution of polycyclic aromatic hydrocarbons (PAHs) was determined in green mussels (Perna viridis) from various sites in coastal waters of Peninsular Malaysia between August 2004 and January 2007, in order to assess contamination by petroleum hydrocarbons. The range of ∑PAHs detected in mussels was from 766 to 110500 (ng/g lipid wt.). High concentrations of PAHs were found in mussel tissues collected near Penang Bridge. The ratios of methyl phenanthrenes to phenanthrene (∑MP/P ratio) for Penang, Kg. Pasir Puteh and Tebing Runtuh (Johore Straits) were greater than 2, indicating extensive input of petrogenic PAHs. The results indicated that male individuals elevated more considerable concentrations of PAHs in their soft tissues in comparison to female individuals. The results of independent sample T-test showed that there were no significant differences (p > 0.05) between male and female mussels analysed in the Pasir Panjang station. Negative significant correlations (r = −0.890, p < 0.01) and (r = −0.0655, p < 0.05), were found between weight and total of PAHs in female and male species, respectively. This indicated that body weight of each individual was not affected by the PAHs concentrations. The present study proposes the use of soft tissue of Perna viridis as a biomonitor of perylene bioavailability and contamination in coastal waters of Peninsular Malaysia

The history of petroleum pollution in Malaysia; urgent need for integrated prevention approach

Petroleum pollution is known as point and non-point source of contaminations in the environment. A major class of petroleum contaminant is groups of compounds consist of two or more fused benzene rings called polycyclic aromatic hydrocarbons (PAHs) that are carcinogenic, mutagenic and toxic. Source identification of petroleum pollution is necessary to prevent pollution entry into the environment. Eight sedimentary cores were obtained from developed and developing areas around Peninsular Malaysia to investigate the historical profile of PAHs, their characteristics and its possible origins. The results showed that the PAHs concentrations varied from very minimum to 2400 ng/g d. w. in average quarter century intervals. Most of the studied locations showed high contribution of PAHs from combusted fuel, coal, biomasses and wood materials except for the southern part of Peninsular Malaysia in which revealed dominance of petroleum products. The findings indicate that PAHs are delivered from different intermediate materials such as asphalt, street dust, vehicular emission and crankcase oil. However, there has been a decline of PAHs input into the marine environment in recent years; petroleum is shown to be a significant cause of marine pollution since the second quarter of 20th century. An overview on sourced materials of petroleum pollution indicates multi-approach necessity toward pollution control, regardless of concentration and possible degradation processes. Various sectors both governmental and non-governmental are needed for prevention and control of petroleum pollution where different sources apparently contribute to the pollution generation process

Use of different tissues of Perna viridis as biomonitors of polycyclic aromatic hydrocarbons (PAHs) in the coastal waters of Peninsular Malaysia

For the first time, in May 2007, the distributions of polycyclic aromatic hydrocarbons (PAHs) were studied in the soft tissues (STs) (mantle, gills, foot, gonad, muscle, byssus, and remaining soft tissues) of the green-lipped mussel Perna viridis, collected from eight geographic locations along the coastal waters of peninsular Malaysia. The STs of the mussels collected from the eastern part of the Johore Straits indicated higher bioavailability of and contamination by PAHs than from other areas. The results also indicated a significantly higher concentration of the lower molecular weight (LMW) PAHs in tissues compared to that of the higher molecular weight (HMW) PAHs, perhaps due to the greater bioavailability of the more water-soluble LMW PAHs or related to a partial biotransformation of the higher molecular weight PAHs. The results also suggest that the differences found in the contents of PAHs in various STs of P. viridis were mainly due to differences between individual PAHs volatility and solubility in water, as well as the mechanism of PAH accumulation by mussels. Of the STs in general, the gonad was shown to contain the highest levels of PAHs, but it is not a potential biomonitoring organ because it is highly influenced by spawning conditions. Isomeric PAH ratios were used to differentiate pollution sources.The findings of the study suggest that STs of P. viridis are good biomonitors of the bioavailability and contamination with PAHs in tropical coastal waters

Revolatilisation of soil-accumulated pollutants triggered by the summer monsoon in India

Persistent organic pollutants that have accumulated in soils can be remobilised by volatilisation in response to chemical equilibrium with the atmosphere. Clean air masses from the Indian Ocean, advected with the onset of the summer monsoon, are found to reduce concentrations of hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its derivatives, endosulfan and polychlorinated biphenyls (PCBs) in air at a mountain site (all in the range 5–20&thinsp;pg&thinsp;m−3) by 77&thinsp;%, 70&thinsp;%, 82&thinsp;% and 45&thinsp;%, respectively. The analysis of fugacities in soil and air suggest that the arrival of summer monsoon triggers net volatilisation or enhances ongoing revolatilisation of the now-banned chemicals HCH and PCBs from background soils in southern India. The response of the air–soil exchange was modelled using a regional air pollution model, WRF-Chem PAH/POP. The results suggest that the air is increasingly polluted during transport by the south-westerly monsoon winds across the subcontinent. Using a multidecadal multimedia mass balance model, it is found that air–surface exchange of HCH and DDT have declined since the ban of these substances from agriculture, but remobilisation of higher chlorinated PCBs may have reached a historical high, 40 years after peak emission.</p

Organic Contaminants in Agricultural and Alpine Streams in New Zealand

Organic contaminants have become widespread in the environment due to the high consumption of materials in the modern lifestyle. The contamination of surface aquatic systems can be particularly crucial because pollutants can pose serious risks to the biological communities residing in these ecosystems. Contaminants can also leach though soil and pollute groundwater resources that are often used as drinking water supply in many parts of the world. Good examples of organic contaminants of concern are pesticides and polycyclic aromatic hydrocarbons (PAHs). In aquatic systems, contaminants can be characterized through different sampling techniques, such as sediment and passive sampling approaches. In the present study, sediment samples were used to investigate the effects of farm management practices on concentrations of halogenated pesticides in streams. The sediment samples were collected from 15 streams arranged in five clusters on the South Island of New Zealand. The streams passed through separate farmlands that were managed using organic, integrated, and conventional practices. The samples were extracted using selective-pressurized liquid extraction (S-PLE) and analysed with a gas chromatograph (GC) coupled with a mass selective detector (MS). The results of the study showed that farm management can negatively affect the pesticide concentrations in streams. Conventional farming was generally associated with higher pesticide concentrations. Organic and integrated farming improved the stream quality, although the streams that passed through these farmlands cannot be considered pesticide-free because the residues of pesticides applied in the past can remain in the environment for a long time. The present study also discusses in detail the principles of aquatic passive sampling, highlighting advantages and disadvantages of the technique. Passive sampling, as opposed to spot measurement approach, provides an integrated record of contaminant concentrations in the environment. This is particularly important for aquatic systems where episodic contamination events are expected to occur. The application of passive samplers normally requires a large quantity of organic solvents to be used in both pre-deployment preparation and analysis steps. In order to minimize the amount of solvent used for the analysis, in the present study a novel method was developed for extracting PAHs from silicon rubber samplers using selective-pressurized liquid extraction (S-PLE), together with post-extraction purification with gel permeation chromatography (GPC). The developed method proved to be satisfactory and the mean recoveries for PAHs using S-PLE and GPC were 75 (%RSD = 20) and 97% (%RSD = 16), respectively. The silicon rubber samplers were used in order to monitor concentration pulses of atmospherically transported PAHs in streams during annual snowmelt. The investigated streams were located in Arthur’s Pass National Park on the South Island of New Zealand. Three sampling sites were chosen; two were located along the Otira River and one along Pegleg Creek River. The passive sampling was conducted in nine consecutive periods from July to December 2010. The samplers were extracted and the resulting extracts were purified using the developed method. All samples were later analysed for PAHs using GC/MS. The results of the analysis showed that PAH water concentrations increased in the study area during the snowmelt period. In addition, the study suggested that weather conditions and sampling site characteristics may have affected the observed PAH concentration patterns at different sites during the study period