Multi-criteria approach for selecting the best solid waste management technologies

The growth in urbanization and industrial activities has caused solid waste management problems. As a solution the integrated approach has been chosen to manage the solid waste. Developing and implementing integrated solid waste management involve combined technologies and alternatives which are suitable with local laws condition. This research showed that Analytical Hierarchy Process (AHP) has the potential as a decision making tool that can be used in selecting process of solid waste management technology. Three levels hierarchy was developed with the goal at the top level, followed by criteria and alternatives. By using this technique, the priority of each considered technology will be determined where technology with the highest priority is more suitable to be developed. Sensitivity analysis was carried out to test the sensitivity of final decision towards inconsistency of judgement. Application of AHP to determine priority in selecting solid waste management technology was explained in this research based on a case study in the Port Dickson Municipal Council. Analysis of result showed that the combination of recycling technology and composting are suitable to be applied in the Port Dickson district

Is Household Smoking a Risk factor for Caries? A Case-Control Study

Recent studies suggested that exposure to household smoking (HHS) could be a modifiable risk factor for caries development among children. Majority of the studies were cross sectional in nature. Therefore, a case-control study was designed to test the hypothesis that HHS is a risk factor to caries experience in permanent teeth. Calculation of sample size was based on the ratio of 1 case to 4 controls. Case was defined as a child aged 13-14 years old with caries in at least one second permanent molar and control was defined as a child from the same age and school with no caries second permanent molars. Matching was done for gender and ethnicity. School dental records provided information on oral health status and oral hygiene status. Information on HHS, socio-economic status, child’s smoking status and child’s oral health practices were obtained from a self administered questionnaire, completed by the children and their parents. The result showed that 55.9% of the case group was exposed to HHS, as compared to 44.1% among the control group. In the final multiple logistic regression model after controlling for important risk factors for caries, children with caries were almost twice as likely to have been exposed to HHS for more than 10 years as compared to children with no caries, (Adjusted OR=1.90 and 95% CI=1.35, 2.60). In addition, children who only received dental care from the school dental service had reduced risk of having dental caries by more than one third (36%) as compared with those who received dental care from school dental service (SDS) as well as had additional dental problem solving visit outside SDS (Adjusted OR=0.64 and 95% CI=0.50, 0.90). It is concluded that exposure to HHS for a long duration (> than 10 years) increase the risk to have caries experience in permanent teeth of children

Rarity and viability value of different type of ecosystem and plants species in tropical forest ecosystem of Bungoh Catchment, Sarawak, Malaysia

Bungoh catchment is located in the southern part of Sarawak, Malaysia and south east of Kuching town and densely covered by tropical forests. A study was conducted to determine the rarity and viability values of plant species and also the rarity and viability values of the four different types of forest ecosystem of Bungoh Catchment. The four major forest ecosystems include the primary forest, old secondary forest, young secondary forest and agroforestry. The numbers of trees were recorded from the entire three different forest ecosystem using single plant method of size 400 square meters (20m X 20m). A total of 373 individual trees representing 148 species were recorded from the four different types of forest ecosystem. Out of 148 species, 22 species were recorded from the primary forest, 72 species were recorded from old secondary forest whereas 37 species were recorded from young secondary and the remaining 17 species were recorded from agroforestry. The rarity and viability value of plants species or ecosystem types is of immediate importance for the biodiversity conservation. The approach is designed for assessment of the rarity and viability values of plants species in the four major forest ecosystems in Bungoh Catchment. The rarity values are measured based on the frequency of certain plants species or ecosystems types are encountered whereas the viability value is assessed by considering three indicators which includes the core area, isolation and disturbances. The results indicate that the rarity value of all the four types of ecosystem namely the primary forest, old secondary forest, young secondary forest and agroforestry were relatively high indicating that the species in the ecosystem are distributed equitably and reflect the commonness of the species. Conversely, the viability value of the entire four ecosystems relatively low indicating that the species are prone to extinction

Gas Chromatography Mono Spectrometry Study Of Malathion Residues In Centella asiatica

Centella asiatica is a herbaceous plant and known as pegaga in Malaysia. It was commonly used as a healing agent and constituent to improve mental ability because contains polyphenols and triterpenes. Malathion is an insecticide that helped to increase value and yields of Centella. asiatica by control the damage caused by crop pests. Study was done in MARDI Serdang to measure malathion residue in Centella. asiatica with different treatment methods using GC-MS. Six plots were randomly selected and samples were taken a day before, a day, three days and five days after the application of malathion. The samples were divided into treated (soaked in tap water and salted water), and untreated groups. The sample was extracted through the liquid-liquid extraction and underwent a clean-up process by a silica gel. The residues were found in; three samples treated with salt water (A1= 19.78 µg/kg, C1 = 8.53 µg/kg and E1= 0.99 µg/kg), one sample treated with tap water (E1=0.44 µg/kg) and two unwashed samples (E1=0.0053 mg/kg and F1=0.0077 mg/kg). Therefore the safest way to consume is by soaked with tap water compared with soaked in salt water and unwashed. However the malathion residue found were below the Maximum Residue Limits set up by US EPA

Is household smoking a risk factor for caries? A case-control study

Recent studies suggested that exposure to household smoking (HHS) could be a modifiable risk factor for caries development among children. Majority of the studies were cross sectional in nature. Therefore, a case-control study was designed to test the hypothesis that HHS is a risk factor to caries experience in permanent teeth. Calculation of sample size was based on the ratio of 1 case to 4 controls. Case was defined as a child aged 13-14 years old with caries in at least one second permanent molar and control was defined as a child from the same age and school with no caries second permanent molars. Matching was done for gender and ethnicity. School dental records provided information on oral health status and oral hygiene status. Information on HHS, socio-economic status, child's smoking status and child's oral health practices were obtained from a self administered questionnaire, completed by the children and their parents. The result showed that 55.9% of the case group was exposed to HHS, as compared to 44.1% among the control group. In the final multiple logistic regression model after controlling for important risk factors for caries, children with caries were almost twice as likely to have been exposed to HHS for more than 10 years as compared to children with no caries, (Adjusted OR=1.90 and 95% CI=1.35, 2.60). In addition, children who only received dental care from the school dental service had reduced risk of having dental caries by more than one third (36%) as compared with those who received dental care from school dental service (SDS) as well as had additional dental problem solving visit outside SDS (Adjusted OR=0.64 and 95% CI=0.50, 0.90). It is concluded that exposure to HHS for a long duration (> than 10 years) increase the risk to have caries experience in permanent teeth of children. Copyright Reserved © Sains Malaysiana