This study aims to fully integrated and validated spatial temporal statistical model using epidemiological data as a predictive model for surveillance and control of DF cases. Kernel-density estimation (KDE) method was carried out by using spatial union analysis in order to predict and visualize the DF hotspot area by monthly basis in the Subang Jaya area. The generated maps were then verified using Receiver operating characteristics (ROC) was performed to validate the DF hotspot simulation model. Spatial analysis showed that the dengue epidemics in Subang Jaya were spatially dependent. This analysis demonstrated spatial clustering of dengue activity which can facilitate prediction of the magnitude, timing and location of future dengue epidemic. The model developed highlights the adaptation capabilities of the approach where the accuracy assessment result showed accuracy about 60% agreements between the hotspot map and the actual DF location data. It can thus be suggested that any future population increase will be associated with increased DF risk in areas which already accommodate this disease environmentally, climatically and socioeconomically. Future risk could be modelled using the same methods. This would help decision maker in choosing which areas should be under intensive treatment to counter mosquito breeding and reduce prevalence of DF.
Spionid polychaetes, Prionospio are one of the dominant polychaetes in the organically enriched sediment of Sriracha Bay, Chonburi, Eastern coastline of Thailand. This study aims at the bioremediation of organically enriched sediment under green mussel rafts by two spionid polychaetes, Prionospio (Prionospio) membranacea and Prionospio (Minuspio) pulchra. The biomass increment from the two spionids in the bioremediation process revealed that P. (P.) membranacea was significantly more efficient in converting the organic waste to biomass in term of body weight than P. (M.) pulchra. The efficiency of the two polychaetes in the reduction of total organic matter in the sediment was not significantly different. The potential in bioremediation of organic matter in sediment by the two spionids was better than other polychaetes used in the bioremediation of the organic waste from aquaculture system. This study showed that spionid polychaetes P. (P.) membranacea, had the potential for future study as bioremediator species of organically enriched sediment from aquaculture system.
The concentrations of haloacetic acids (HAAs) in both indoor and outdoor swimming pools were assessed for cancer and non-cancer health risks with water samples collected during the summer and rainy seasons from two sources. Results showed that average concentrations of HAA5 (MCAA, DCAA, TCAA, MBAA, and DBAA) in both indoor and outdoor pools ranged from 74.28 to 163.05 µg/L which was higher than USEPA and WHO water quality standards. Cancer and non-cancer risk values of HAA5 exposure from both swimming pool types were acceptable risks based on USEPA recommendation (10 -6-10-4 and <1, respectively). The highest cancer and non-cancer risk values of HAAs exposure were females for indoor pool and children for outdoor pool, respectively. Cancer and non-cancer risk values of HAA5 exposure from outdoor pool were higher than indoor pool and during the rainy season, respectively. Results indicated that monitoring and control of water quality and accumulated organic substance in swimming pools should be followed to maximize health risk reduction from HAA exposure.
This study aims to determine prevalence of microorganisms in the air state and those associated particulate matter (PM) in a hot arid environment (Makkah city, Saudi Arabia) in relation to time of the day, PM concentration and meteorological conditions during the period between July and September 2014. PM and black smoke samples were collected on cellulose nitrate membrane filters during the daytime (8.00 am - 20.00 pm) and the nighttime (20.00 pm - 8.00 am). PMs, filters were eluted in buffer phosphate and aliquots were spread plated onto the surfaces of trypticase soya agar, malt extract agar, and starch casein agar media for counting bacteria, fungi and actinomycetes associated PM, respectively. Airborne microorganisms were collected using an Andersen two stage impactor sampler equipped with Petri plates containing the previously mentioned agar media. The Andersen two-stage viable cascade impactor sampler separates particles into coarse (≥8 µm) and fine (≤8 µm) size fractions. Airborne microorganisms were taken at three day time-scales: in the morning (8 am - 10 am), at the afternoon (13.00 pm - 16.00 pm) and in the evening (22.00 pm - 1.00 am). The average concentrations of PM (149.5 µg/m3) and smoke (57.03 µg/m3) were higher in the daytime and nighttime, respectively. The greatest concentrations of microorganisms associated PM were found in the daytime, however the peak concentration of airborne microorganisms was found in the evening time. Fine microbial fraction constituted ~60% - 75.9% of the total microbial concentrations. Positive correlations were found between bacteria with PM concentration in the daytime and meteorological conditions at the nighttime. Temperature and relative humidity positively affected survivability of microorganisms associated PM at the nighttime and airborne fungi as well. This study helps understand distribution pattern of microorganisms in the atmosphere of a hot-arid environment.
Biosorption is a promising method for removing heavy metals from wastewater, evidenced by several studies on the high efficiency and cost-effectiveness of its practical usage. In the present study, cuttlebone powder (CB-P) and cuttlebone modified via carbonization at 400°C (CB-M400) were used to remove Pb (II) from an aqueous solution. The adsorbents were characterized using a scanning electron microscope (SEM) and an X-ray diffractometer. An adsorption study was carried out at different initial pHs, biosorbent doses, and initial Pb (II) concentrations, in batch experiments in order to evaluate the optimum conditions for Pb (II) removal. The results showed that CB-P obtained a larger specific surface area (8.41 m2/g) than CB-M400 (2.69 m2/g); however, the calcite in CB-M400 displayed a remarkably higher sorption capacity for Pb (II) than the aragonite in CB-P. The carbonization of organic matter in CB-P resulted in a higher calcium carbonate content and the formation of fixed carbon, increasing the adsorption capacity of CB-M400. Optimum conditions for removal of Pb (II) occurred at pH 4.0 with 0.2 g/L of the biosorbent dose. In an equilibrium study, Langmuir’s isotherm was fixed at R2 > 0.9; the maximum capacities were calculated to be 869.57 mg/g for CB-P and 1,573.56 mg/g for CB-M400. In a kinetic study, a pseudo second-order model was fixed; the higher adsorption rate was found in CB-M400.
