Due to the increasingly documented prevalence of diarrhoeal diseases in Malaysia, a number of water-related programmes have been implemented in an attempt to improve health status through the reduction of incidence of waterborne communicable diseases associated with poor public water supplies. The implicit assumption underlying these projects is that the enhancement of the physical infrastructure, and subsequent improvements in the quality of the water supply, will substantially reduce water-related disease. The present study questions this hypothesis and uses a socio-ecological model as a framework to assess risk factors associated with the increased probability of waterborne disease. Research is centred on Port Dickson, a district which typifies existing water and sanitation conditions in much of semi-rural Malaysia. Health services utilization data and a 268-household diarrhoeal morbidity survey were used to measure the burden of illness of waterborne disease within the district and to identify predictors of morbidity. It was concluded that although treatment facilities will reduce the health burden in the region, a number of behavioural and sanitation factors may be more important and could act to minimize the potential impacts of improved water quality.
The H2S water screening test and the membrane filtration faecal coliform count were compared with Escherichia coli counts for water samples collected from household water sources and domestic drinking water in rural Malaysia. Water samples were taken from 151 wells, 44 taps supplying water from the treated municipal supply and 192 domestic stored water supplies. E. coli were detected in 20% of the samples (42% of wells, 7% of tap water and 6% of drinking water). Excellent correlation (Spearman's rank correlation rs = 0.93) was found between the faecal coliform and E. coli counts for all sample types. The H2S method was poorly correlated whether read at 18 or 30 h. False positive rates were highest for well water, and false negative rates were highest for both well and drinking water samples, with low E. coli counts. The faecal coliform test was an excellent predictor of the presence of E. coli in these water samples, while the H2S test was very inadequate.
In response to a recorded increasing incidence of diarrhoea in Tumpat District, Malaysia, a case-control study was performed to identify modifiable risk factors for the transmission of diarrhoea, in children aged 4-59 months. Ninety-eight pairs of children, matched on age and sex, were recruited prospectively from health centres. Exposure status was determined during a home visit. Interviewers were 'blinded' as to the disease status of each child. Odds ratios were measured through matched pair analysis and conditional logistic regression. Risk factors for diarrhoea identified were: reported--drinking of unboiled water, storage of cooked food before consumption and bottle feeding; and observations--animals inside the house and absence of washing water in latrines. Water quality, source of drinking water, reported hand washing behaviour, indiscriminate defecation by children, cup use and the absence of a functional latrine were not associated with diarrhoea. Nonsignificant associations were found for: accessibility of washing water source, type of water storage container and use of fly covers for food.
Intestinal protozoa are found in all communities in Malaysia and among all ethnic groups. Prevalence of intestinal protozoa is not affected by ethnicity but by living conditions. Communities with both basic amenities of safe water supply and proper toilets have lower prevalence than those with one or none of the amenity. Cryptosporidium is an important intestinal protozoon in Malaysia and should be included in future field and laboratory studies and also in laboratory diagnosis for pathogens. Much interest will be centered on Blastocystis hominis in future studies in view that it may be a cause of diarrhea.
A cross-sectional study was conducted in four Orang Asli settlements, in the district of Kuala Langat, to determine the knowledge and practice associated with diarrhoeal disease among the Orang asli children (0-5 years). It was seen that the social and environmental factors of the settlements were poor. Only 26% of the households had sanitary latrines and 36% had access to safer water supplies. Ninety-five percent of them had monthly income below the national poverty line. The diarrhoeal incidence was high, ie 240/1000 and the most affected were the older children in the age group of 49 - 60 months. Knowledge of diarrhoeal disease was poor. But the majority (84.2%) knew that breast feeding is the best milk for the child in order to avoid diarrhoeal disease.
The association of arsenical poisoning with the development of skin cancer is well-known. In Malaysia, arsenic has been shown to coexist with tin in tin-mining land. Our preliminary investigation has shown that the level of arsenic in well water from a tin-mining area is high. We report 3 patients with cutaneous lesions typical of chronic arsenical poisoning such as hyperpigmentation, keratoses and skin cancer. These patients have positive histories of previous domicility in tin-mining areas. We conclude that these patients developed chronic arsenical poisoning from drinking well water polluted with arsenic from the tin-mining soil.
A simple water iodizing system, which incorporates the Venturi principle in combination with the controlled release mechanism of a silicone-sodium iodide elastomer, for the iodization of rural piped-water supply in the control of endemic iodine deficiency has been developed and its effectiveness evaluated in three Iban longhouse villages in the iodine-deficient district of Lubok Antu, Sarawak. Urines were collected for iodine assays from women aged 15-40 years before and at 6 and 12 months after the connection of the iodinating device; goiter assessment was performed on the women at the start and end of the 1-year study. Water samples were collected for iodine assays at 2-weekly intervals. In all three villages, significant and sustained increases in median urinary iodine excretions, reaching levels recommended for an iodine-sufficient population, were observed; goitre prevalences were reduced in all the villages (by 22.6% to 35.8%). The iodine levels in the water ranged from 34 micrograms/l to 212 micrograms/L. In the control village, median urinary iodine excretions remained essentially unchanged but a small increase in goiter prevalence was observed. The iodized water was well received by the villagers and no adverse effects of water iodization were observed. The system functioned unattended throughout the one year period. The cost of providing supplemental iodine via the iodizing device is approximately 60 cents (U.S.) per family per year which is affordable by either the Government or the villagers. It is concluded that the iodizing system offers a new cost-effective strategy for the control of endemic iodine deficiency in Sarawak and may have applications in other areas with similar water sources.
This study was conducted to determine the health status of aboriginal ("Orang Asli') children aged 0-12 years in Post Brooke, Gua Musang, Kelantan. This is done by appraising the environmental status, patterns of illnesses including communicable diseases and usage of health resources. Six villages were selected randomly from 12 villages in the area; 179 families were interviewed, 200 under-12-year-olds were examined and their blood samples taken for haemoglobin (HB) estimation as well as malarial screening. Water supply through Gravity Feed System (GFS) was used by 134 families (70.2%) whilst the rest obtained water direct from the river for the purpose. Only 63.6% of families boiled their drinking water 56.4% families threw rubbish indiscriminately, while 82.1% used the river as their toilets. Eighty-seven percent of the families saw the village medicine man first when ill. Forty (22.2%) children had had serious illnesses including malaria and 24 were admitted to hospitals. 15% of the children had never been immunized. A total of 102 (51%) children were pale and 90 (45%) had brown hair. Eighty nine (44.5%) of the children were anaemic (Hb < 10 gm/di). Sixty-nine children (34%) had dental caries. Forty-two (21%) had distended abdomen and 37 (18.5%) had hepatomegaly. Out of 84 stool samples examined, 67 (79.8%) had helminthic ova. Of all families, 47.1% gave a past history of at least one baby among their children who had died due to one reason or another. The health status of this community (especially children) was low that it warrants special attention.
Malaysia is a rapidly developing country with a very young population, about 36% of which are below the age of 15 years. The standard of child health has improved greatly. However, there are great changes in the morbidity and mortality patterns of childhood diseases relating mainly to an improved standard of living; availability of safe water supply and adequate sanitary latrines; a higher literacy rate; rapid industrialisation and urban migration. The infant mortality rate has droppedfrom 50.1 per 1,000 livebirths in 1986 to 10.4 in 1995, and similar trends apply also to neonatal, perinatal and toddler mortality rates. Nevertheless, current major child health problems are those relating to events in the perinatal period and to infections. Despite improvements in the standard of neonatal care with the use ofhigh technology, the commonest cause of certified deaths still occur in the neonatal period. A rapid and inexpensive screening test for G6PD deficiency, a disease present in 2-3% of the population, is now widely available and, together with the use of phototherapy is largely responsible for the declining incidence of kernicterus in the country. Infections remain an important cause of morbidity and mortality although their patterns have changed. The very high (>95%) WHO-EPI-vaccines coverage rate is linked to the great reduction in the incidence of diphtheria, pertussis, tetanus, poliomyelitis and measles. Childhood tuberculosis is less common now, with about 250 - 300 reported cases per year and TB meningitis is rare with about 30-40 reported cases/year. The hepatitis B carrier rate is high (5%) and the introduction of routine newborn hepatitis B vaccination in 1989 is expected to have a positive impact as is the immunisation of young girls against rubella introduced in 1985 in reducing the incidence of congenital rubella syndrome. The incidence of malaria has declined but remains prevalent in the interiors of PeninsularMalaysia and in Sabah and Sarawak. Filariasis is largely under control. Unfortunately, despite great efforts at mosquito control, dengue virus infection remains a major problem with thousands of cases reported every year. Children are most susceptible to dengue haemorrhagic fever with many dying from the shock syndrome. The incidence of acute gastroenteritis has also dropped with most cases being due to a viral aetiology. Acute respiratory infections, mostly viral in origin, account for most attendances at paediatric outpatient services. Although staphylococcal and streptococcal impetigo and pneumonia are common, the incidence of streptococcal related diseases like rheumatic fever and acute glomendonephritis is rapidly declining. The nutritional status of children has improved in tandem with the rise in the standard of living, but subclinical malnutrition is prevalent, particularly among urban squatters and the rural poor. There is a disturbing decline in breastfeeding among urban working mothers. Poor weaning practices and food habits are responsible for the common occurrence of nutritional anaemia (5%) among infants and young children. Greater prosperity, rapid industrialisation and urbanisation have resulted in changes in the childhood disease pattern where non-communicable diseases assume greater importance as the problems of malnutrition and infection are gradually overcome. Road traffic accidents are a major killer and home accidents, largely preventable, are an important cause of morbidity and mortality. Childhood cancer, with about 550 new cases a year, is an important cause of death beyond infancy. Major congenital malformations, with a 1% prevalence rate, cause much ill-health. Thalassaemia is a particularly common genetic disease with fl thalassaemia gene frequency of about 5%. The prevalence of asthma is increasing, with a rate of 13.9% in the Kiang Valley but the prevalence of asthma-related symptoms is much higher. Physical, sexual child abuse and neglect, abandoned babies, substance abuse are but signs of stress of modern city living and peoples inability to cope with it. Although the general standard of child health has greatly improved, there are several states where it is still not satisfactory. In Sabah where there is a large illegal immigrant population, the infant mortality and infection rates are relatively high. In Kelantan and Trengganu, it is common for parents to refuse permission for a lumbar puncture required to treat meningitis. Other still deeply entrenched, culturally-related adverse health practices include : a fatalistic attitude to illness; a preference for traditional practitioners of medicine resulting in late treatment; and 'doctor-hopping' with unrealistic expectations of 'instant cure'. Childhood illnesses that are uncommon in Malaysia include: cystic fibrosis, coeliac disease, ulcerative colitis, Crohns disease, Sudden Infant Death Syndrome, Encopresis, enuresis and epiglottitis due to Haemophilus Influen:ae.
A survey of malnutrition and helminth infections among 268 pre-school children living in the Kuala Betis Orang Asli resttlement villages in Kelantan. The prevalence of helminth infections was 47.4% with Ascaris lumbricoides being the most common helminth (43.9%), followed by Trichuris trichiura (29.7%) and hookworm (6.3%). The prevalence of Ascaris lumbricoides and Trichuris trichiura infections increased with age, with the highest prevalence found in the 6-7 years age group. The overall prevalence of stunting, underweight and wasting were 61.7%, 60.4% and 17.5% respectively. Both stunting and underweight were significantly higher among the infected children. Factors associated with helminth infections in the pre-school children were older age group, poor water supply and households with more than 5 members. Rountine regular deworming is recommended based on the World Health Organisation recommendations for school children.
This paper describes the nutritional status of pre-school children and analyzes its relationship to various household socio-economic indicators. Padi, rubber and fishing villages from the Functional Groups Study (1992-1996) were selected for having a high prevalence of child undernutrition, and all children between the ages of 12 and 72 months were measured for their weights and heights in April-May 1998. The NCHS reference values were used to calculate z-scores, which were categorised according to WHO (1983) recommendations. Children between minus 2SD and minus 1SD of reference median were classified as mildly malnourished. Prevalence of underweight was higher (30.5%) than stunting (22.3%), while wasting was only 9.7%. Padi villages had the highest prevalence of undernutrition, followed by fishing, and then rubber villages. Mean household incomes were found to be significantly lower for children with worse nutritional status, and undernutrition was higher in households below the poverty line income. The odds ratios for having stunted children were significantly higher for households whose heads were agricultural own-account workers (OR 3.66, 95% CI = 1.37-9.79), agricultural waged workers (OR 2.75, 95% CI = 1.06-7.10), and non-agricultural manual workers (OR 2.49, 95% CI = 1.04-6.00) compared to non-manual workers. Various household socio-economic indicators showed significantly higher odds ratios for underweight, stunting and wasting. After adjusting for confounding effects by logistic regression analysis, however, only mother's education was found to be a significant predictor for stunting, while poverty level and access to piped water supply were significant predictors for both underweight and stunting. Households without livestock were significant predictors for wasting. Thus, this study identified specific socio-economic factors that should be prioritized for policy and research towards the amelioration of childhood malnutrition in rural areas.
This paper presents the socio-economic profile of households in the Family Dynamics Study (FDS) (1997-2001) and makes comparisons with the earlier Functional Groups Study (FGS) (1992-1996). For the current study, FGS villages with a high prevalence of child malnutrition were purposively selected. In each village selected, all households were included, and interviews with a structured questionnaire were conducted in April-May 1998. Incomes were generally low and incidence of poverty was high; 49.6% of the households were under the poverty line income, of which 37.2% were poor and 12.4% were hard core poor. Overall, only 23.2% of heads of households were in agricultural occupations, others being primarily waged workers and petty traders. Livestock rearing was widespread (57.8%), and most households (90.4%) owned at least one motorised vehicle, the most common being the motorcycle. The majority of households had refrigerators (73.6%), washing machines (58.8%), and televisions (91.1%); but telephones (42.2%), mobile phones (6.1%) and computers (2.3%) were less common. Although 99.7% of households had electricity supply and 95.1% had either a flush or pour flush latrine, only 57.4% had piped water supply. In comparison to the FGS, poverty in the current study is lower (49.6% of FDS households are poor compared to 55.2% of FGS households), the proportion of household heads in agricultural occupations is also lower (26.9% compared to 55.3%), while all other socioeconomic indicators were better, except for piped water supply, which remains inadequate for households in the current study.
Toxicity testing of four heavy metals (Cd, Cu, Mn and As) using four species of tropical marine phytoplankton, Chaetoceros calcitrans, Isochrysis galbana, Tetraselmis tetrahele and Tetraselmis sp., was carried out in multiwell plates with test volumes of 2 mL and the results compared to those of standard, large volume, shake-flasks. IC50 values (concentrations of metals estimated to inhibit 50% growth relative to the control) were determined after 96 hours based on automated O.D. readings measured in Elisa microplates by a Multiskan spectrophotometer. Good agreement was achieved between O.D. readings and cell counts indicating that this new method is a simple, economical, practical and rapid technique for toxicity testing, and provides good reproducibility of IC50 values. Results of the toxicity tests indicate that Cu was the most toxic metal (average IC50 values ranging from 0.04 to 0.37 mg L(-1)), followed by Cd (0.06-5.7 mg L(-1)), Mn (7.2-21.4 mg L(-1)) and As (33.9-319.3 mg L(-1)). Test species had different degrees of sensitivity to the metals tested, with I. galbana and C. calcitrans the most sensitive to Cu, Cd and Mn. Based on these findings it is recommended that the existing Malaysian Interim Standards for Marine Water Quality for Cd and Cu be reviewed.
Temperature variation is an important factor in Everglade wetlands ecology. A temperature fluctuation from 17 degrees C to 32 degrees C recorded in the Everglades may have significant impact on fish dynamics. The short life cycles of some of Everglade fishes has rendered this temperature variation to have even more impacts on the ecosystem. Fish population dynamic models, which do not explicitly consider seasonal oscillations in temperature, may fail to describe the details of such a population. Hence, a model for fish in freshwater marshes of the Florida Everglades that explicitly incorporates seasonal temperature variations is developed. The model's main objective is to assess the temporal pattern of fish population and densities through time subject to temperature variations. Fish population is divided into 2 functional groups (FGs) consisting of small fishes; each group is subdivided into 5-day age classes during their life cycles. Many governing sub-modules are set directly or indirectly to be temperature dependent. Growth, fecundity, prey availability, consumption rates and mortality are examples. Several mortality sub-modules are introduced in the model, of which starvation mortality is set to be proportional to the ratio of prey needed to prey available at that particular time step. As part of the calibration process, the model is run for 50 years to ensure that fish densities do not go to extinction, while the simulation period is about 8 years. The model shows that the temperature dependent starvation mortality is an important factor that influences fish population densities. It also shows high fish population densities at some temperature ranges when this consumption need is minimum. Several sensitivity analyses involving variations in temperature terms, food resources and water levels are conducted to ascertain the relative importance of temperature dependence terms.
Some of the many tools used for watershed management are mathematical and computer models for wasteload allocations. QUAL2E is one of the most popular water quality models used for such purposes. The question arises as to whether the model is applicable in a different climate such as that in the tropics. In this study, QUAL2E was used to model Sg. Selangor River in Malaysia using the predictive equations for reaeration coefficient (k2) within the model and the measured reaeration coefficients for the river. The study results indicated that use of the reaeration coefficient (k2) measured at Sg. Selangor River did give the lowest standard error (SE) for the simulation of water quality during the 7Q10 low-flow period which is considered as the worst scene scenario in water quality modeling. But during calibration and validation using actual low-flow discharge data, the measured reaeration coefficients did not give the lowest standard error (SE). In conclusion, the results indicated that QUAL2E is applicable in tropical rivers when used with the modeled river parameters (i.e. hydraulic parameters, meteorological conditions etc.). Measured reaeration coefficients produced good results and several predictive equations also produced comparatively good results.
The complex nature of natural organic matter (NOM), and the impact of this matter on drinking water quality have necessitated the characterization studies of NOM. A fluorescence technique for the characterization of NOM in Malaysian river water is reported. Water samples from several river sampling sites were collected and concentrated using a low-pressure reverse osmosis (LPROM). Solid phase extraction (SPE) using C18 extraction cartridges were used to fractionate the water samples into humic and non-humic fractions. To differentiate and classify various types of humic substances, fluorescence was applied in emission, excitation and in synchronous-scan modes. A synchronous spectral profile was found to be able to differentiate humic and fulvic acids better than the emission or excitation spectra. Synchronous excitation spectra showed different spectral patterns for the water samples due to different origin. All water samples showed the presence of both fulvic and humic acids.
This paper describes an investigation on the effect of microbial removal using IMF for high quality drinking water production. The comparison of IMF and IMF-PAC configuration was carried out in the study to highlight the importance of PAC in the system. The specific objective of this study was to study the effect of PAC adsorption in the IMF-PAC system particularly in removing microbial substances from contaminated raw water. A bench scale IMF-PAC configuration using a flat sheet microfiltration membrane was set up for experimental purposes. Experimentally, the result has shown high removal of microbial substances with the IMF-PAC system compared to IMF. The result of E. coli removal achieved was below the detectable level due to the microbial size, which is bigger than membrane pore size. The addition of PAC has shown a direct effect on total microbial removal. The adsorption of microbial onto PAC surfaces reduced the amount of smaller microbial present in permeate samples. As a conclusion, the configuration of IMF is a promising separation process in removing microbial substances, especially when the system is combined with PAC.
Environmental monitoring was carried out at Upper Layang Reservoir situated in Masai, Johor, Malaysia. The study shows that thermal stratification and natural mixing of the water column do exist in the reservoir and the level of stratification varies at different times of the year. Artificial destratification via diffused air aeration techniques was employed at the reservoir for two months. The results show that thermal stratification was eliminated after a week of continuous aeration. The concentrations of iron and to a lesser extent manganese in the water column was also reduced during the aeration period.