Distribution, bioaccumulation, and health risk assessment of organochlorines across the riverine ecosystem of Punjab Province, Pakistan

This study was designed to assess the distribution of organochlorines (OCs) in fish species, their spatio-temporal variations, bioaccumulation potential, and associated human health risks via dietary intake. The levels of twenty-three organochlorine pesticides (OCPs) and thirty-five polychlorinated biphenyls (PCBs) were analyzed in six fish species collected from the riverine ecosystem of Punjab Province, Pakistan. The results indicated that the mean levels of Σ23OCPs were 74.1 ng/g ww and 184 ng/g ww, and for Σ35PCBs the levels were 38.8 ng/g ww and 74.8 ng/g ww in herbivorous and carnivorous fish species, respectively. The most abundant contaminants in all fish species were DDTs (65%) and HCHs (14%) among OCPs and heavier PCB congeners (62%) among PCBs. As for dioxin-like PCBs, the WHO toxic equivalency values (ng TEQ/g ww) were in the range of 0.21 (Cyprinus Carpio) to 2.38 (Rita Rita), exceeding the maximum allowable limit of 0.004 ng TEQ/g, ww by the European Commission. Spatio-temporal analysis indicated relatively higher OC levels in winter season with elevated concentrations in fish samples from industrial zone. The bioconcentration factor (L/kg) values ranged from 723 to 2773 for PCBs and 315 to 923 for OCPs in all fish species, with higher levels were reported in carnivorous species. The human health risk assessment at both 50th and 95th percentiles revealed the absence of any significant non-carcinogenic risk as calculated HR was less than 1. However, the critical carcinogenic risk was found to be associated for most of the contaminants, signifying the dietary exposure to OCPs and PCBs might pose the public health concern.

Organochlorines in the riverine ecosystem of Punjab province, Pakistan: contamination status, seasonal variation, source apportionment, and ecological risk assessment

The aim of the present study was to determine the occurrence, spatio-temporal variations, source apportioning, and ecological risk assessment of selected PCBs and OCPs in surface water and sediments collected riverine environment of Punjab province, Pakistan. The concentration of ΣOCPs (water: 64-455 ng/L; sediments: 117-616 ng/g) and ΣPCBs (water: 2-132 ng/L; sediments: 3.27-200 ng/g) was found comparatively higher than the levels reported from other parts of the world. The higher concentrations of DDTs and HCHs were detected in both studied matrices, whereas among PCBs, CB-28, 49 and CB-37, 82 were dominant in water and sediments, respectively. The isomeric ratios including α-HCH/γ-HCH, (DDE + DDD) / DDTs, and α /β-endosulfan reflected the recent use of lindane, technical DDT, and endosulfan in the study area. The WHO-TEQ values of DL-PCBs ranged from 3.6 × 10^-6 to 0.115 ng/L and 8.7 × 10^-6 to 0.157 ng/g in surface water and sediments in both seasons, respectively. The spatial variation analysis revealed that the sites in the industrial and agricultural zones were highly contaminated. The OCPs and PCBs fluxes to downstream areas were estimated to be 12.4 tons/year and 1.9 tons/year, respectively. The significant ecological risks were estimated to be posed by OCPs and PCBs, as their levels in 67% and 62% of surface water and sediment samples were exceeding the threshold limits, highlighting effects to ecological integrities.

Analysis of environmental sustainability of e-waste in developing countries - a case study from Pakistan

The electronic waste generation rate is increasing drastically at a rate of 3 to 5% per year in developing countries. The aim of this study is to analyze the environmental sustainability and economic benefits of such e-waste management in the developing economies like Pakistan. The life cycle assessment (LCA) method has been employed for streamlined impact analysis of the end-of-life processing of e-waste focusing mainly on laptop computers and liquid crystal display (LCD) desktop computers in Pakistan. The method of cumulative exergy extraction from the natural environment (CEENE) has also been deployed for the relative assessment of resources' consumption of e-waste recycling versus landfilling scenario. The determined impact scores are 1.79E + 03 kg CO₂ eq., 7.19E-07 kg CFC-11 eq., 1.02E + 03 kg 1,4-DCB, 7.13E + 01 kg 1,4-DCB, and 3.41E-03 kg Cu eq. in climate change potential, stratospheric ozone depletion, ecotoxicity potential, human noncarcinogenic potential, and mineral resource depletion impact categories, respectively. The results of CEENE analysis reveal that approximately 80% of the impact on natural resources is reduced by the efficient recycling of e-waste. The comparative assessment of respective scores for current and target material weight recovery (MWR) indicators represented that by increasing the MWR indicator by 33.8% for laptop computers and by 27.2% for LCD computers, the country will achieve an annual economic benefit of US $191.56 million. This is greatly significant for a transitional shift towards e-waste revalorization while realizing the objectives of sustainable resource consumption. Innovative improvement measures ensuring economically feasible, energy-efficient, and environment friendly waste collection, treatment, and recycling practices present an invaluable opportunity for developing countries.

A comparison of waste recycling facilities for their contribution of heavy metals and trace elements in ambient air

A multi-elemental analysis, including heavy metals and trace elements in ambient air samples, was conducted for computers, wires, lead batteries, and iron extraction facilities in Lahore by proton-induced X-ray emission (PIXE) spectroscopy. The data obtained from PIXE analysis revealed the presence of Mg, Al, Zn, S, Pb, K, Ti, Fe, Si, K, and Cr elements at e-waste recycling facilities. The computer dismantling site revealed a higher concentration of Fe (634.7 μg/m³), Al (176.8 μg/m³), Pb (135.4 μg/m³) and Zn (122.5 μg/m³) in the air samples. The decreasing order of heavy metals and trace elements contribution at the computer dismantling site was as Si > Fe > Al > Pb > Zn > Mg > Ca > Cr > K > S > Ti. Similarly, at wires/cables burning site, a higher concentration of Fe, Al, and Pb (829.8 μg/m³, 184.5 μg/m³ and 115.6 μg/m³, respectively) were observed, and the elements revealed a descending trend as Si > Fe > Al > Zn > Pb > Mg > Ca > Cr > Ti > K > S. The lead batteries dismantling site showed the highest Pb concentration (141.2 μg/m³) due to the disassembling of lead acid batteries. Al, Zn, Fe, and Cr also revealed higher concentration in air samples and exhibited a declining trend as Si > Fe > Al > Pb > Zn > Cr > Ca > Mg > Ti > K > S. However, the highest concentration of Fe (865.7 μg/m³) was detected in air samples of iron extraction sites besides Al and Zn. The descending order of trace elements contribution was Si > Fe > Al > Zn > Mg > K > Ca > Ti > S. Furthermore, the correlation between workers' awareness and their possible health impacts were also examined in the study. Most of the workers were less aware of the hazardous impacts. Majority of workers and residents were suffering from a respiratory illness (27.5% and 32.5%), kidney failure (15% and 22.5%), and neurological disorders (15% and 7.5%), respectively, due to exposure of airborne particulate matter which could be correlated with the higher concentration of heavy metals such as Pb, Cr, Zn, and Fe in the ambient air at the e-waste recycling sites.

Human Health Risk Assessment by Dietary Intake and Spatial Distribution Pattern of Polybrominated Diphenyl Ethers and Dechloran Plus from Selected Cities of Pakistan

A class of intractable bio accumulative halogenated compounds polybrominated diphenyl ethers (PBDEs) was studied. Specifically, PBDEs and dechloran plus (DP) contamination in wheat and the assaulted environment—agricultural soil and dust—from metropolitan cities of Pakistan was the focus. The exposure of brominated flame retardants (BFRs) to humans, their probable toxicological impact on health, source apportionment, and the spatial tendency of BFRs were studied. Chromatographic analysis was performed, and concentrations (ng g⁻¹) of ΣPBDE and ΣDP in soil, dust, and cereal crops were estimated in a range from 0.63 to 31.70 n.d. to 6.32 and n.d. to 3.47, respectively, and 0.11 to 7.05, n.d. to 4.56 and 0.05 to 4.95, respectively. Data analysis of source apportionment reflected that the existence of solid and e-waste sites, long-range transport, urban and industrial fraction can be the potential source of PBDE and DP pollution. Moreover, potential hazardous risks to human health across the study area via the dietary intake of cereal foods were deemed trifling, and were gauged on the basis of existing toxicological data.

COVID-19 and frequent use of hand sanitizers; human health and environmental hazards by exposure pathways

Till date no medication or vaccine is available to cope with the COVID-19 infection and infection rate is increasing drastically across the globe. Only preventive measures and healthy life style with efficient immune system have been suggested by WHO to fight and stay safe from COVID-19. WHO recommended alcohol based hand sanitizers for frequent hand hygiene, which are mainly made up from ethanol, isopropyl alcohols, hydrogen peroxides in different combinations. These preparations may become toxic to human health and environment when misused. These chemicals have known toxic and hazardous impact on environment when released by evaporation. In early five months of 2020, American Association of Poison Control Center reported 9504 alcoholic hand sanitizer exposure cases in children under the age of 12 years and recognized that even a small amount of alcohol can cause alcohol poisoning in children that is responsible for confusion, vomiting and drowsiness, and in severe cases, respiratory arrest and death. Furthermore, frequent usage of said hand sanitizers has reported increased chance of antimicrobial resistance and chance of other viral diseases. Current review is designed with main objective to highlight the toxic and serious health risks to human health and environment by frequent using hand hygiene products with alcohols based formulations.

Sustainability and CDM potential analysis of a novel vs conventional bioenergy projects in South Asia by multi-criteria decision-making method

In this study, the multi-attribute utility theory model, one of the most widely utilized multi-criteria decision-making methods, is employed to analyze the relative sustainability and cleaner development mechanism (CDM) potential of a novel bioenergy project in Pakistan and four registered CDM bioenergy installations in China, India, Sri Lanka, and Thailand. Four major sustainability evaluation criteria selected for the study are technology, economy, environment, and social aspects, whereas "simple multi-attribute rating technique" (SMART) and "additive synthesis method" were utilized for the calculation of weighting factors. The most significant indicator was emission reduction, and least significant indicator was job creation with 24% and 15% respective weightages, in the sustainability scoring. Moreover, for three considered evaluation scenarios, (I) base case, (II) per kilowatt, and (III) per kilowatt hour, the bioenergy project in Pakistan has the highest comparative sustainability values of 0.735, 0.592, and 0.492 respectively. This analysis will provide an insight assistance to developing countries for establishing sustainable energy installations under CDM.

Phytoremediation potential of Pistia stratiotes and Eichhornia crassipes to remove chromium and copper

Phytoremediation is a cost-effective and eco-friendly process to remove heavy metals from water. A small-scale experiment was conducted to determine the phytoremediation efficiency of two macrophytes, i.e. Pistia stratiotes and Eichhornia crassipes for the removal of chromium and copper from the prepared metal solutions of different concentrations (2, 4, 6, 8 mg/L) for a period of one month. Both aquatic macrophytes showed different efficiency for the removal and accumulation of Chromium (Cr) and Copper (Cu). The dry biomass of both macrophytes increased over the period of time. The average accumulation of chromium in roots and leaves of P. stratiotes was 85 mg, 56 mg and copper was 96 mg and 70 mg, respectively whereas the average accumulation of chromium in roots and leaves of E. crassipes was 90 mg, 53 mg and copper was 86 mg, 50 mg, respectively. Higher absorbance of metals was observed in roots as compared to the leaves of both macrophytes. The concentration of metals in the solution significantly decreased from day 1 to day 30. The results of one-way ANOVA showed that removal of Cr was significantly (p < .05) greater in E. crassipes and removal of Cu was significantly (p < .05) greater in P. stratiotes.

Appraisal of the heat vulnerability index in Punjab: a case study of spatial pattern for exposure, sensitivity, and adaptive capacity in megacity Lahore, Pakistan

In this study, the heat vulnerability index has been developed for a megacity Lahore. Although Pakistan stands at 12th rank among highly exposed countries to climate change, very little research has been dedicated in exploring the heat-related vulnerability of exposed populations. We have applied the principal component analysis with varimax rotation on well-established indicators of exposure, sensitivity, and adaptive capacity to determine the heat vulnerability. This study has resulted in two principal components sharing 70.4% variance. Principal component 1 comprises pre-existing illness, population density, housing density, education, and normalized difference vegetation index with following significant (> 0.4) loading values 0.91, 0.91, 0.91, 0.57, and - 0.773, respectively, and principal component 2 combines the nature of housing material (0.964) followed by the water availability (0.962) and minority status (0.539). The hot spot analysis and overlay analysis have also been applied on the extracted component, and the resultant co-occurrence of high variable class, high vulnerability, and hot spots of vulnerability helped to grip those areas which imperatively require the applications of heat-related health interventions. The heat vulnerability index developed in our study clarifies that the most vulnerable populations are confined in the central vicinities of Lahore and less vulnerable are those which inhibit towards the outskirts of the city.

Environmental impact and economic sustainability analysis of a novel anaerobic digestion waste-to-energy pilot plant in Pakistan

A novel medium-large industrial-scale, anaerobic digestion (AD) waste-to-energy pilot plant has been investigated in terms of cost-benefit, environmental impact, and economic sustainability. This pilot plant exclusively features a multi-digester AD system induced by motorized stirring, methane purification, compression, storage and digestate-fertilizer processing systems, and subsequent electricity generation. The operational productivity and success of the pilot plant has been proven on a variety of waste feedstock substrates in the form of cow-buffalo manure and potato waste. The plant has an average energy productivity of 384 kWh/day and an annual rate of return was estimated to be 15.4%. The life cycle environmental impact analysis deliberated the significant impact potentials in terms of climate change (kg CO₂ equivalent), and fossil depletion (kg of oil equivalent) for three selected substrates: 100% cow-buffalo manure (CBM), 100% potato waste (PW), and a mixture of 75% CBM and 25% PW. The results show the climate change potential of 70 kg, 71 kg, and 149 kg and fossil depletion potential of - 2.43 kg, - 16.45 kg, and 18 kg per 2000 kg of substrate slurry, respectively. As such, the substrate of 100% CBM posed the least climate change impacts whereas 100% PW has been established most effective under the fossil depletion category.

Correction to: Ecological risk assessment of metals in sediments and selective plants of Uchalli Wetland Complex (UWC)-a Ramsar site

The correct image of Figure 4 is shown in this paper. The original article has been corrected. Fig. 4: Scree plot of heavy metals in sediments. The graph shown in upper right corner shows the concentration of principle components variables in a loading plot.

Ecological risk assessment of metals in sediments and selective plants of Uchalli Wetland Complex (UWC)-a Ramsar site

Wetlands act as kidneys of land and facilitate remediation of metals and other harmful pollutants through uptake by aquatic macrophytes. The aim of the present study was to investigate metal concentrations in sediments and plants, sources of metal origin, and contamination level in Uchalli Wetland Complex. Sediment samples were collected from 15 randomly selected sites. Metal concentrations (Cd, Pb, Ni, Cu, Zn, Cr, As, Mn) in sediments and macrophytes were determined during summer and winter seasons using the inductively coupled plasma technique. Metal concentrations in sediments during summer and winter seasons were in the order as follows: As > Mn > Zn > Cr > Ni > Cd > Pb > Cu and As > Mn > Zn > Cr > Ni > Pb > Cd >Cu respectively. All analyzed metals were within European Union (EU) limits. In macrophytes, these metals were in the order as follows: Mn > As > Ni > Zn > Cr > Cd > Cu > Pb and As > Mn > Zn > Ni > Cr > Cd > Pb during summer and winter seasons respectively. Contamination degree (C_d) (1.023-5.309) for these lakes showed low contamination during both seasons; mC_d values (below 1.5) showed very little contamination degree, while the pollution load index (0.012 to 0.0386) indicated no metal pollution in these lakes. PCA applied on sediment showed that Pb, Zn, Cr, Cu, and Cd had anthropogenic sources of origin. As and Mn were due to natural processes while Ni could be resultant of both anthropogenic and natural sources. PCA on macrophytes showed that Ni, Pb, Cr, Zn, Cu; Cd, As; Mn had anthropogenic, natural, and anthropogenic + natural sources of origin. The study concluded that metal concentrations in sediments were not up to dangerous level.

Investigating the drinking and surface water quality and associated health risks in a semi-arid multi-industrial metropolis (Faisalabad), Pakistan

Urban areas under the influence of multi-industrial activities with arid and semi-arid environments witness the significant increase in environmental pollution especially in the water sector. The present study evaluated the water quality and associated health risk assessment through heavy metal pollution. Drinking (n = 48) and surface (n = 37) water samples were collected from semi-arid multi-industrial metropolis, Faisalabad, Pakistan. Physio-chemical and biological parameters and different metals (Al, As, Ba, Cd, Cr, Cu, Fe, Pb, Ni and Zn) were investigated using standard procedures and multivariate water quality assessments. Many physio-chemical and biological parameters and metals especially arsenic were exceeding the permissible limit of Punjab environmental quality standards and the World Health Organization. The results from water quality index showed that < 56% samples have poor, < 8% have very poor and < 6% have unsuitable water quality for drinking purposes. Water quality for the Gugera Branch Canal was found suitable with medium sodium (alkalinity) and salinity hazards, while it was found poor with magnesium absorption ratio. Hazard quotient (HQ) values for arsenic were found at the threshold level (HQ > 1) and carcinogenicity was found in case of arsenic and chromium (1 × 10^-4) in adults and children. Semi-arid weather combined with different anthropogenic activities and unusual water features provoked metal contamination. Results of the present study can deliver basic information for effective management of water in the most populous and industrial areas.

Treatment of textile effluents with Pistia stratiotes, Eichhornia crassipes and Oedogonium sp

Phytoremediation by aquatic macrophytes is a promising technology with higher efficiency and no energy consumption. For this purpose, two macrophytes (Pistia stratiotes, Eichhornia crassipes), and an alga (Oedogonium sp.) were used to treat textile effluents rich in COD, BOD, dyes, and heavy metals (Pb, Fe, Cd, Cu). The aim of the study was to focus on comparative phytoremediation potential of these species by their metal removal capability. During 7 days experiment (day 0-day 6), the results showed that Oedogonium sp. was the best for COD removal and decolorization. Eichhornia crassipes was the best for BOD and heavy metal removal and proves more efficient than Pistia stratiotes and Oedogonium sp. However, Pistia stratiotes was found to accumulate more concentrations of Pb and Fe than Eichhornia stratiotes.

Spatio-temporal variations in physico-chemical parameters and potentially harmful elements (PHEs) of Uchalli Wetlands Complex (Ramsar site), Pakistan

Uchalli Wetlands Complex (UWC) is located in District Khushab, Pakistan, which comprised of three lakes named Khabeki, Uchalli, and Jahlar. The UWC Pakistan is one of the Ramsar sites of international importance. However, the information regarding water quality parameters and concentration of potentially harmful elements (PHEs) is relatively short. Present study focused on spatio-temporal variations in the physico-chemical parameters and PHE (Cd, Pb, Ni, Cu, Zn, Cr, As, Mn) concentrations in water and fish samples using inductively coupled plasma. Sampling was done in summer (August 2016) and winter (January 2017) seasons. The overall concentrations of PHEs in water were in the following order: Mn > Zn > Cu > Cr > Ni > Cd > Pb > As for Khabeki; As >Ni > Cr > Mn > Zn > Cu > Cd > Pb for Uchalli; and Mn > Zn > Ni > Cu > As > Cr > Cd > Pb for Jahlar Lake. PHE concentration in fish followed the order Ni > Cd > Mn > Pb > Cu > Zn > Cr > As. PHEs analysis showed that Mn; Ni and As; and Ni and Mn in summer were above the Pakistan Environmental Quality Standards (PEQS) and World Health Organization (WHO) standards in Khabeki, Uchalli, and Jahlar Lakes respectively while in winter, Mn; Cd, Ni, and As; and Ni and Mn were higher than standard values in Khabeki, Uchalli, and Jahlar Lakes respectively. In fish samples, only Cd (0.0942) was higher in summer as compared to winter (0.0512) while other seven PHEs observed were higher in winter. Conclusively, the metal pollution index showed that water quality of UWC is not very fit for human consumption directly. The bioconcentration factor results indicated potential to accumulate PHEs, i.e., Cd (29.4375 and 9.4814), Pb (16.66 and 4.375), and Ni (4.9875 and 6.206), in fish during both sampling campaigns. Target hazard quotient (THQ), target carcinogenic risk (TR), hazard index (HI), estimated daily intake (EDI), and international safe standard limits of PHEs for fish species indicated that fish from UWC is safe for human consumption. Variations in physic-chemical parameters and PHE concentration were observed spatially and temporally that could be caused by precipitation amount or natural geochemistry of the lakes' crust. The water quality was not suitable for direct human consumption. Fish was only found in Khabeki Lake that had potential to accumulate Cd, Pb, and Ni more as compared to other studied PHEs.

Monitoring and spatiotemporal variations of pyrethroid insecticides in surface water, sediment, and fish of the river Chenab Pakistan

There is a serious concern regarding freshwater resources of Pakistan which have been mismanaged and now are depleting extensively due to other reasons like intensive application of agricultural pesticides and insecticides. The present study was conducted to determine the concentrations of cypermethrin, deltamethrin, permethrin, and bifenthrin in the samples of water, sediments, and fish collected from various locations of River Chenab, Pakistan, during summer and winter seasons. These locations include namely Marala, Khanki, Qadirabad, and Trimu Headworks. High-performance liquid chromatography (HPLC) was deployed for analysis and determination of pyrethroid concentrations in these samples. The analytics show the order of pyrethroid concentrations in river as fish> sediment>water. Whereas maximum concentrations of 0.472 μg g^-1 found in fish and minimum concentrations were determined in water, i.e., 0.087 μg L^-1 at the sampling locations of Trimu and Marala headworks, respectively. Moreover, highest mean concentrations of pyrethroid, i.e., 1.248 μg g^-1 in fish were detected in winter season as compared to summers, i.e., 0.087 μg L^-1. However, all the values of pyrethroid were found to be lower than the maximum permissible levels specified by EU and WHO-FAO. Whereas the levels of deltamethrin and permethrin in water were found much higher than the specific limits set by EU.

Seasonal and spatial quantitative changes in Aedes aegypti under distinctly different ecological areas of Lahore, Pakistan

OBJECTIVE

To find out the variations in larval and adult density of Aedes aegypti in different seasons under different ecological conditions.

METHODS

This study was undertaken in all the nine towns and the cantonment board of Lahore, Pakistan, during four seasons in 2011, 2012 and 2013. Ovitraps were placed in houses in residential areas and were visited weekly in rainy and post-rainy seasons each year to determine the presence of immature and mature forms of Ae.aegypti. Densities of these were measured by ovitrap index and per man hour density, respectively. Correlation coefficient and coefficient of determination between ovitrap index, per man hour density and climatic variables were established. SPSS 19 was used for data analysis.

RESULTS

Ovitrap index and per man hour density values were lower in early rainy season compared to late rainy and early post-rainy seasons. These became lowest in late post rainy season. Strong correlation coefficient and its determination between ovitrap, per man hour density and climatic variables were observed.?

CONCLUSIONS

Density of immature and mature forms of Ae.aegypti was influenced by environmental degradation.

Phytoremediation of organochlorine and pyrethroid pesticides by aquatic macrophytes and algae in freshwater systems

Extensive use of Pesticides in agriculture and its surface runoff in river water is a major environmental concern. The present study evaluated the phytoremediation potential of Eichornia crassipes, Pistia strateotes and algae (Chaetomorpha sutoria, Sirogonium sticticum and Zygnema sp.) for organochlorine and pyrethroid pesticides. Water and plant samples were extracted by liquid phase and solid phase extraction respectively and analyzed by high-performance liquid chromatography. Eleven treatments (T1-T11) with and without plants were used for phytoremediation of organochlorine and pyrethroid pesticides. During the experiment, P. strateotes, E. crassipes and algae (C. sutoria, S. sticticum and Zygnema sp.) showed the highest removal efficiency with 62 (71% root, 29% shoot), 60 (67% root, 33% shoot), and 58% respectively for organochlorine and 76 (76% root, 24% shoot), 68 (69% root, 31% shoot), and 70% respectively for pyrethroids for the respective aquatic plants. Dissipation rate constant of treatments with plants (T2, T3, T5, T6, T8, and T9) was significantly higher (p < 0.05) as compared to that of treatments without plants (T10 and T11, control) for both organochlorine and pyrethroid. The bioconcentration factor of pyrethroid treatments (T3, T6, and T9) was significantly higher (p < 0.05) as compared to that of organochlorine treatments (T2, T5 and T8). The removal efficiency of E. crassipes, P. strateotes and algae (C. sutoria, S. sticticum and Zygnema sp.) for pyrethroids was significantly higher (p < 0.01) as compared to that of organochlorine.

The distribution of Aedes aegypti (diptera, culicidae) in eight selected parks of Lahore, using oviposition traps during rainy season

OBJECTIVE

To investigate the seasonal distribution of immature habitat of Aedes aegypti mosquito species and its association with environmental and climatic conditions.

METHODS

This descriptive study was conducted in eight parks in Lahore, Pakistan, over three years from 2011 to 2013.A total of 2,496 ovitraps were placed in environmentally different conditions near water channels, thick vegetation cover/shades, clean/unclean sites and places where there was lot of human activity. Each trap was monitored weekly in early rainy, late rainy, early post-rainy and late post-rainy seasons of each of the three years to determine the presence of Aedes aegypti larvae by measuring ovitrap index. SPSS19 was used for data analysis.

RESULTS

The value for ovitrap index was found highest in late rainy season (20.83). High association was observed with environmental conditions (p<0.05) as this index was high in micro-habitats close to water channels, shades and residences. The association of ovitrap index with water channel, vegetation cover, cleanliness and human activity was significant in all four seasons (p=-0.000). With temperature, this association was significant only in early post-rainy (p=-0.000) and late post-rainy seasons (p=0.024). With humidity, it was significant in early post-rainy and late post-rainy seasons (p=-0.000 and p=0.024) while with rainfall, the association was significant in all seasons (p=0.000).

CONCLUSIONS

Abundance and occurrence frequency of Aedes aegypti had a positive association with deteriorating environmental and seasonal climatic conditions.

Sero-surveillance of dengue in the city Lahore, Pakistan

OBJECTIVE

To conduct sero-surveillance of dengue cases, and to find out the demographic and socio-economic status of dengue patients.

METHODS

This community-based, cross-sectional, descriptive study was conducted at the Institute of Public Health, Lahore, Pakistan, from July to December each year in 2011, 2012 and 2013, and comprised patients suspected to have dengue. Blood samples of dengue patients in five randomly selected union councils of the 10 towns of the city were subjected to the dengue test. Information about demographic and socio-economic characteristics was obtained with the help of pre-tested semi-structured questionnaire. SPSS 16 was used for data analysis.

RESULTS

Of the 5,544 dengue patients, 5.263 (94.9%) patients were diagnosed in 2011, followed by 25(0.45%) and 256(4.6%) in 2012 and 2013, respectively. Sero-surveillance of these dengue patients in 2011 showed that on an average 3,094 (58.79%) cases had primary infection, 1,506 (28.61%) had old infection, while only 663 (12.6%) had secondary infection. Similar pattern was observed in 2012 and 2013. It was found that 2,379 (42.9%) participants were aged between 15-30 years and 2,203 (39.7%) between 31-45 years. Besides, 3,618 (65.3%) participants were males and 1,926 (34.7%) females. Also, 2,865 (51.4%) participants were labourers, 2,746 (49.5%) and 2,260 (40.7%) were educated up to primary and secondary levels, respectively. Although sporadic dengue cases were recorded from July to December, most of the cases were observed in late rainy and early post-rainy seasons.

CONCLUSIONS

The incidence of dengue was highest in people of 15-45years of age, particularly males, labourers and those with low income.

Ecological risk assessment of an open dumping site at Mehmood Booti Lahore, Pakistan

A robust risk assessment of Mehmood Booting Open Dumping (MBOD) site has been carried out by developing holistic risk assessment framework. Framework mainly comprises on baseline study, hazard identification, and risk quantification and evaluation. Physico-chemical analysis of groundwater and leachate, health risk assessment, and estimation of gas emissions from the site were carried out for risk evaluation. LandGEM 3.02 modelling software was used to measure the gas emissions. Analysis of leachate showed that all parameters were exceeding the WHO standard limit. Water samples were found polluted with heavy metals and total coliform contamination. Health survey inferred that problems which were faced by the majority of respondents were respiratory problems (80%). LandGEM model estimated that total landfill gas (TLG) emitted from the site for the year 2014 was 1.760E+05 Mg/year, CH₄ emission was 5.445E+06 Mg/year, CO₂ emission was 1.290E+05 Mg/year and for non-methane organic compound emission was 2.021E+03 Mg/year. It can be concluded that in the near future, almost all the water locations are possibly threatened with leachate contamination due to the continued accumulation of solid waste at MBOD site. The study recommends that new sanitary landfill sites should be designed to minimize the adverse effects associated with solid waste disposal and to preclude further pollution to surface water, groundwater, soil, and air.

Assessing spatio-temporal trend of vector breeding and dengue fever incidence in association with meteorological conditions

Th aim of this study is to investigate spatio-temporal trends of dengue vector breeding and epidemic (disease incidence) influenced by climatic factors. The spatio-temporal (low-, medium-, and high-intensity periods) evaluation of entomological and epidemiological investigations along with climatic factors like rainfall (RF), temperature (T_max), relative humidity (RH), and larval indexing was conducted to develop correlations in the area of Lahore, Pakistan. The vector abundance and disease transmission trend was geo-tagged for spatial insight. The sufficient rainfall events and optimum temperature and relative humidity supported dengue vector breeding with high larval indices for water-related containers (27-37%). Among temporal analysis, the high-intensity period exponentially projected disease incidence followed by post-rainfall impacts. The high larval incidence that was observed in early high-intensity periods effected the dengue incidence. The disease incidence had a strong association with RF (r = 0.940, α = 0.01). The vector larva occurrence (r = 0.017, α = 0.05) influenced the disease incidence. Similarly, RH (r = 0.674, α = 0.05) and average T_max (r = 0.307, α = 0.05) also induced impact on the disease incidence. In this study, the vulnerability to dengue fever highly correlates with meteorological factors during high-intensity period. It provides area-specific understanding of vector behavior, key containers, and seasonal patterns of dengue vector breeding and disease transmission which is essential for preparing an effective prevention plan against the vector.

Predicting dengue outbreak in the metropolitan city Lahore, Pakistan, using dengue vector indices and selected climatological variables as predictors

OBJECTIVE

Dengue viruses have rapidly spread in Southeast Asia, particularly in Pakistan, during the last few years, so the present study was undertaken to formulate a model for predicting dengue outbreak.

METHODOLOGY

A panel data using STRATA statistical software was employed to determine the effects of entomological indices, Per Man Hour Density (PMHD), Minimum Infection Rate (MIR) and selected climatic variables on dengue patients by using Fixed Effects (FE) and Random Effects (RE) models.

RESULTS

Results showed that R2 value, reflecting fitness of model was 0.3026 in FE model and 0.3028 in RE model, while the Coefficient and P [Z] values in RE model, indicating individual fitness of any variable in the model, revealed that PMHD, MIR, Air Temperature and Relative Humidity had positive impact on the number of dengue patients, while rainfall exhibited negative impact..

CONCLUSIONS

For every 10 unit rise in PMHD, MIR, atmospheric temperature and relative humidity, the number of patients increased by 4.01, 15.88, 3.10 and 5.73, respectively, while an increase in rainfall by 10 mm will result in decrease in the number of dengue patients by -1.01. Further analysis of socioeconomic and demographic variables of participants is suggested.

Water-borne diseases, cost of illness and willingness to pay for diseases interventions in rural communities of developing countries

BACKGROUND

Almost one third of the global population is living in developing South Asia where disease occurrence is high especially in rural areas and people are unaware of water-borne diseases and cost of illness.

METHODS

The quantitative approach involved questionnaire based study (n=50 households). The community awareness, the occurrence of water-borne diseases with related cost of illness and community participation for the introduction of health interventions for water-borne diseases were evaluated through cross-tabulations, correlations, and ANOVA.

RESULTS

Majority (40%) of the community had no knowledge of water-borne diseases except some had little knowledge of diarrhea and typhoid. Diarrhea followed by stomach diseases was widespread in the community. Population below poverty level was bearing the cost of illness around US$ 0.6-1.2 (Rs 50-100) per day followed by low and average income level with direct cost of US$ 2.3 (Rs 200) per day. The indirect cost of illness had showed increasing trend between US$ 2.3-4.7 (Rs 200-400) per day with increase in income levels. Maximum willingness to pay (WTP) for water supply and sewerage system was US$ 3.6 (Rs 300) and US$ 1.2 (Rs 100) per month respectively. Income and water supply demand was strongly correlated with acceptability to pay for the facilities (r = 0.319, 0.307; P< 0.05). Income had a strong influence on WTP for water and sewerage system (r = 0.805, 0.797; P< 0.05).

CONCLUSION

To maintain rural health, water-borne diseases can be reduced by introducing health interventions like proper water and sanitation facilities.