Norela Sulaiman

Pesticide risk assessment: A study on inhalation and dermal exposure to 2,4-D and paraquat among Malaysian paddy farmers

A cross-section analytical study was conducted to evaluate the risk of pesticide exposure to those applying the Class II pesticides 2,4-D and paraquat in the paddy-growing areas of Kerian, Perak, Malaysia. It investigated the influence of weather on exposure as well as documented health problems commonly related to pesticide exposure. Potential inhalation and dermal exposure for 140 paddy farmers (handlers of pesticides) were assessed. Results showed that while temperature and humidity affected exposure, windspeed had the strongest impact on pesticide exposure via inhalation. However, the degree of exposure to both herbicides via inhalation was below the permissible exposure limits set by United States National Institute of Occupational Safety and Health (NIOSH). Dermal Exposure Assessment Method (DREAM) readings showed that dermal exposure with manual spraying ranged from moderate to high. With motorized sprayers, however, the level of dermal exposure ranged from low to moderate. Dermal exposure was significantly negatively correlated with the usage of protective clothing. Various types of deleterious health effects were detected among users of manual knapsack sprayers. Long-term spraying activities were positively correlated with increasing levels of the gamma-glutamyl transpeptidase (GGT) liver enzyme. The type of spraying equipment, usage of proper protective clothing and adherence to correct spraying practices were found to be the most important factors influencing the degree of pesticide exposure among those applying pesticides.

Surfactants in South East Asian Aerosols

Environmental Context.Surfactants are present in all atmospheric aerosols with potential effects on surface tension, cloud droplets and even human health. They appear to be anionic and associated with yellow aqueous extracts, suggesting a humic-like character. These surfactants are probably derived from the oxidation of combustion-generated soot (from vehicles and forest fires). Abstract.The concentration of surfactants in aerosols was determined at several sites in South East Asia, Bangi, Penang and Kota Kinabalu in Malaysia and Bangkok, Thailand, as methylene blue active substances (MBAS) and ethyl violet active substances (EVAS) for anionic surfactants and disulphine blue active substances (DBAS) for cationic surfactants. The methodology used is based on the formation of extractable ion-association complexes of surfactants and dye in organic solvents followed by spectrometric measurement of the intensity of the extracted coloured complex. Results showed surfactants in aerosols are mostly in the anionic form as MBAS and EVAS, and higher in aerosols collected in congested areas, especially in times of forest fires. Concentrations are in the range of 34.6 to 285.0 pmol m−3 for MBAS and 129.9 to 932.2 pmol m−3 for EVAS. Several different types of soot and humic acid seem possible sources of surfactants in atmospheric aerosols. Laboratory experiments suggested that combustion products, especially from motor vehicles, are important primary sources of surfactants in aerosols. There is also some laboratory evidence that there are secondary sources for these surfactants in aerosols, possibly humic-like substances (HULIS) from the oxidation and photochemical reaction of soots and humic acid.

Relationships observed between Trichoderma inoculation and characteristics of rice grown under System of Rice Intensification (SRI) vs. conventional methods of cultivation

The System of Rice Intensification (SRI), a management-based approach for improving rice production, has demonstrated various positive effects on rice plants’ growth, resilience and yield. These effects have been attributed in part to symbiotic interactions between rice plants and the microbes that live around, on and inside them; but research on this is still very limited. To examine such relationships, a multifunctional symbiotic fungus Trichoderma asperellum SL2 was evaluated to assess its effects, if any, on the germination and growth of young seedlings and then the subsequent performance of rice plants during their crop cycle. Greenhouse studies were conducted under gnotobiotic conditions to assess any effects associated with inoculating rice seeds with Trichoderma asperellum SL2 compared with uninoculated controls in terms of seedling establishment, an essential part of SRI methodology; and then assessing the capacity of this fungus to enhance the growth, physiological characteristics, nutrient uptake, and yield of rice plants growing under simulated SRI conditions. Results showed that the presence of Trichoderma asperellum SL2 in association with SRI cultural practices led to significant increases in rice seedling growth, germination rate, vigour index, and chlorophyll content, and elicited more favourable phenotypical responses from given genotype potential. The research observations further illustrated that for some parameters, there were no significant differences between inoculated and uninoculated SRI plants, both giving results superior to those for conventionally-grown plants even when inoculated. This indicated that SRI growing conditions are more favorable for Trichoderma to contribute towards the growth, physiological traits, nutrient uptake, and yield of plants, whereas conventional management methods diminish or inhibit these effects. Focused research remains to be done to establish how aerobic microbes such as Trichoderma can affect and accelerate the performance of rice plants being grown in SRI environments above and below ground.

Fish scale deformation analysis using Scanning Electron Microscope: New potential biomarker in aquatic environmental monitoring of aluminum and iron contamination

Fish scale has the potential to be a rapid biomarker due to its structure and high possibility to come into contact with any pollutant in the aquatic environment. The scale structure consists of osteoblastic cells and other bone materials such as collagen where it is possible to form a molecular complex with heavy metals such as aluminum and iron. Hence, aluminum and iron in water could possibly destroy the scale material and marked as a scale deformation that quantitatively could be analyzed by comparing it to the normal scale structure. Water sampling and fish cage experiment were performed between June and July 2011 in Porong river which represented the water body that has high aluminum and iron contamination. The filtered water samples were preserved and extracted using the acid-mixture procedure prior to measurement of the aluminum and iron concentrations using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), while samples for total suspended solid (TSS) analysis were kept at 4 °C i...

Delineating risk zones and evaluation of shelter centres for flood disaster management along the Pahang River Basin, Malaysia

Shelter centres are important locations to safeguard people from helpless situations and are an integral part of disaster risk reduction (DRR), particularly for flood DRR. The establishment of shelter centres, and their design based on scientific assessment, is crucial. Yet, they are very much related to the geographic location, socio-economic conditions and the livelihoods of the affected communities. However, many parts of the developing world are still lagging behind in ensuring such scientific design. Considering the flood disaster in 2014 that affected the residents living along the Pahang River Basin, in this study we delineate the communities at risk and evaluate the existing shelter centres to determine how they reduce people’s vulnerability to the risks associated with rural and urban landscapes. We used spatial analysis tools to delineate risk zones and to evaluate existing evacuation systems. A flood disaster risk map was produced to determine which communities are living with risks. Subsequently, the distribution of shelter centres examined whether they are able to support people living at the flood risk zones. These centres were also evaluated using a set of international guidelines for effective disaster shelters. This reveals that the number of shelter centres is not adequate. The designation and designing of shelter centres are not being done scientifically. The maps produced here have a lot of potential to support disaster management decisions, in particular site selection and the prioritisation of centres. The study concludes with a set of guidelines and recommendations for structural and non-structural measures, such as alternative livelihoods and the potential of ecotourism, which may improve the resilience among flood-affected communities; and the decision-making process for the overall flood DRR initiatives.

Increasing rice plant growth by Trichoderma sp.

Trichoderma sp. is a plant growth promoting fungi in many crops. Initial observation on the ability to enhance rice germination and vigor have been reported. In this study, the effectiveness of a local isolate Trichoderma asprellum SL2 to enhance rice seedling growth was assessed experimentally under greenhouse condition using a completely randomized design. Results showed that inoculation of rice plants with Trichoderma asprellum SL2 significantly increase rice plants height, root length, wet weight, leaf number and biomass compared to untreated rice plants (control). The result of this study can serve as a reference for further work on the application of beneficial microorganisms to enhance rice production.

Diversity and Abundance of Insects as Bioindicators of the Environmental Impacts of Tin Mining in Bangka Island, Indonesia

Satu kajian telah dijalankan untuk menentukan efek aktivitas pertambangan timah pada kelimpahan dan keragaman serangga dan memilih/menyaring kelompok taksonomi potensial sebagai kandidat potensial bagi bioindikator lingkungan yang baik. Pengambilan contoh dilakukan pada 28 Mei−12 Juni 2008 pada empat stasiun. Dua stasiun ditempatkan dalam daerah pertambangan (stasiun B1 dan B2) sementara dua stasiun control ditempatkan di sekitar daerah hutan lindung (stasiun B3 dan B4). Pengambilan contoh menggunakan empat metode uji perangkap piring kuning, perangkap lekat, perangkap cahaya, jarring sapuan, dan perangkap lubang. Sejumlah 3850 individu serangga memiliki 110 suku dan 493 morfospesies telah diidentifikasi, dan Lepidoptera ditemukan merupakan ordo serangga terbesar yang mewakili jumlah tertinggi. Aktivitas pertambangan telah mengakibatkan keragaman dan kelimpahan serangga terganggu dibandingkan dengan daerah hutan lindung. Terdapat perbedaan yang signifikan (p0,05) faktor-faktor abiotik (pH, humus tanah, kelembapan relatif dan suhu udara) terhadap kelimpahan serangga. Jumlah morfospesies terbesar adalah pada suku Noctuidae, sedangkan individu paling melimpah adalah suku Formicidae. Sebanyak 18 suku telah diikenal berpotensi sebagai biopenunjuk yaitu: Culicidae, Syrphidae, Tipulidae, Alydidae, Cicadellidae, Formicidae, Gelechiidae, Arctiidae, Nymphalidae, Pteroporidae, Cosmopterigidae, Drepanidae, Geometridae dan Noctuidae, Aeschinidae, Libellulidae, Tetrigidae dan Tridactylidae. Kata kunci: Keragaman, kelimpahan, bekas tambang, serangga, biopenunjuk