The present study has employed an advanced GIS based statistical technique for spatial interpolation of lifetime carcinogenic risk to OCPs in water and sediments from tributaries of River Chenab. The findings revealed that among all detected isomers, DDT exhibited the highest concentrations (mean 14.41 ng/l: range 9.33 - 20.21 ng/l and mean 16.47 ng/l: range 10.55 - 21.24 ng/g) for water and sediment, respectively. Results of OCPs fingerprints revealed the presence of dicofol confirmed fresh input of OCPs isomers along with the DDTs (Dichloro-diphenyl trichloroethane) historical usages in water bodies. The evaluation of ecological risk to benthic organisms' fish, daphnia and green algae (RQ 2 x 10(2)) indicated that DDTs (DDD, DDE) pose potential hazardous risks (>1) to fish species across all the studied sites. Moreover, Spatial interpolation of the lifetime carcinogenic risk denoted the sites along downstream zone surpassed the permissible limit. The non-carcinogenic risk (& sum;HQ) ranged from 2 x 10(-3) - 1.0 with the highest value for DDT, indicating DDT as a potential hazard through oral exposure (& sum;HQ >= 1). In the case of sediments results of SQGQs (Sediment Quality Guideline Quotient) levels for DDE (Dichloro-diphenyldichloromethane) and DDD (Dichloro-diphenyl dichloroethylene) denoted a severe biological risk to ecological integrities. The findings comprehend the more inclusive monitoring of OCPs usage and distribution in the studied region to reduce risks ecological integrities and to promote good health and wellbeing's.

Decomposition of organic waste in dumping sites and landfills prompts the uncontrolled emission of greenhouse gases which enhances global warming and related issues. The present investigation estimated the total landfill gas, methane, carbon dioxide and non-methane organic compounds emissions from Mahmood Booti dumping site located at Lahore, Pakistan from 1996 to 2045. LandGEM 3.02 model was utilized to evaluate the gas emission with the volumetric methane 50%, production potential (170 m(3)/Mg), and methane generation rate (0.050/year). The findings demonstrated that organic and food wastes had the maximum quantity in the solid waste stream (63.46%). Methane measured from solid waste was 1.150E+03 (Mg/year) in 1997 in the first year after waste was accepted by landfill while the maximum methane generation rate happened from 2014 to 2018, i.e., from 4.049x10(4) to 4.654x10(4) Mg/year, respectively. The study finding highlighted that all gases emissions have an increasing/rising trend up to 2021 and then gradually their level will decrease because most of the organic fractions of solid waste would degrade with time. The findings of this study can be used to identify the impacts and contribution of MBODS in the global emission of greenhouse gases. The study concludes that proper management of landfill gas will not only decreases greenhouse gas emissions, diminishing adverse impacts on public health but can also be used as a sustainable energy source.

Environmental risk assessment is one of the key tools in environmental engineering. This risk assessment can be qualitative or quantitative and it is based on preliminary studies i.e., baseline study for waste disposal sites. Even though the literature exists on baseline study in general, still there is a lack of guidance regarding development of a site-specific baseline study model for a waste disposal site. This study has two-fold aim, firstly, how to develop site-specific baseline study model for a selected dumping site, and secondly, how this site-specific baseline study can support the environmental engineering via mathematical risk estimation. Mahmood Booti Open Dumping Site (MBODS) is selected to demonstrate the development and application of site-specific baseline study model. This is followed by building a framework that shows how the output of the baseline study can lead to environmental engineering via mathematical risk estimation. The paper provides a mechanism of how to construct a bespoke baseline-study model that is readily useable, avoiding procurement of expensive computer software and yet smoothly connecting with the follow-on stages of the risk assessment. The work presented in this paper can be reproduced repeatedly to create site-specific baseline study models for risk assessment of other waste disposal sites in a cost-effective, consistent and cohesive manner.

Abstract The water quality of the freshwater streams of Pakistan has been degraded with time. The present study aims to explore the water quality and ichthyofauna diversity from the lotic water bodies of the Sialkot. Ten sampling sites were evaluated for pollution levels and ichthyofauna of the Sialkot region. Physicochemical parameters such as pH, temperature, biological oxygen demand (BOD), and total dissolved substance (TDS) were found to be disturbed. In addition, correlation analysis of water quality parameters was studied. The strongest positive correlation (1.0) was observed between alkalinity and bicarbonate. In contrast, a robust positive correlation (0.99) was observed between EC and TDS, whereas pH shows a moderate, weak negative (-0.30) correlation with EC, TDS, Alkalinity, and Bicarbonate, respectively. Moreover, a total of 22 fish species belonging to 10 families were studied and identified. The composition of the fish assemblage mainly belongs to the family Cyprinidae (41%), while the rests of the families contribute 59% to fish assemblage. Our results indicate that the amount of pollutants and overfishing by using pesticides and illegal mesh size is the main reason for reducing the fish population. During the current study, we found surface water quality of streams is being degraded day by day due to the accumulation of pollutants from industrial and domestic sewage waste. It is recommended that severe measures are needed to stop such water contamination, and regular monitoring should be undertaken to monitor the water quality in the study area.

This study analysed heavy metals from little egret (Egretta garzetta). Egret’s Eggs, egg shells, food (fish and insects), blood, meat samples (thigh, liver, and chest), water, soil and sediments samples were collected from the two selected sites of the study area. Samples were analysed on flame atomic absorption spectrometer after acid digestion. Detected metals were found almost inline of concentrations when compared with the both sites. Among detected metals Mn was found higher in concentration (µg/g) i.e. 18.509 followed by Zn i.e. 9.383, Ni, Cu, Pb and Cd. Sediment exhibited higher levels (µg/g) of metals (25.061) followed by the meat (19.044) egrets food (18.825), excreta (16.26), blood serums (4.577), eggs (3.626) and water samples (2.432).The level of metals in sediments of the study are showed environmental concerns. Health risks were also investigated that were compared to guidelines of WHO and FAO threshold limits. It was found a marginal health risk to life through detected metals. This study revealed that little egret are good bio-indicator for the screening and investigation of contaminates presence in the environment.

The current study was focused on selected quality parameters of water, heavy metal contents of water, sediments and fish from Poonch river. Sediments, water and fish samples were gathered including six different sites in the period of April to June 2015. During the study period the mean value recorded for water quality parameters were pH 9.20, mv Oxidation Reduction Potential (ORP) 32.2, Dissolved (Oxygen) DO 6.95 mg/l, Electrical Conductivity (EC) 252.96µS/cm and 271.91 µg/cm, Total Dissolved Solids (TDS) 197.03, Salinity 0.77, Turbidity 3.02, Temperature 31.65 and Pressure 13.37. Mean values recorded for heavy metal absorption in river water, sediments and fish were below the maximum permissible levels. The aim of current study was to show that water is good for the existence of fish survival and its growth. So, this study exhibits that the part of Poonch River, Azad Jammu and Kashmir having water quality parameters and heavy metals were within the tolerable range and no harmful effects on the fish growth and reproduction.

Lakes are most diverse and interactive ecosystems in the world. In this study physiochemical parameters were determined of Mangla Dam Lake which is in District Mirpur Azad Jammu and Kashmir (AJK). Concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were determined in samples of water, sediment, muscle, gills, intestine, liver, and kidneys of fish of the study area. Water samples showed average pH 7.64, Turbidity 2.59 NTU, Conductivity 461 µm/cm, TDS 205 mg/L and Salinity 0.22 mg/L. Low dissolved oxygen of 3.43 mg/L is recorded here. The analyzed data was compared with the international guidelines. In water concentration of Cd > Pb > Zn > Ni > Cr > Mn > Cu. In sediment concentration of Mn > Cr > Zn > Ni > Cu > Cd > Pb. Heavy metal concentrations decreased in muscles as Cr > Zn > Pb > Cd > Mn > Cu > Ni. In gills Zn > Cr > Pb > Mn > Cd > Cu > Ni. In intestine, Zn > Cr > Cu > Mn > Pb > Cd > Ni. In liver, Zn > Cr > Cu > Pb > Mn > Cd > Ni. In kidneys Zn > Cr > Cd > Pb > Cu > Mn > Ni.

Present study was designed to obtain estimation about ground water quality of Bhimber, Azad Jammu and Kashmir (AJK), Pakistan. A total of 12 water samples were collected from different localities of study area to analyze for various physicochemical and biological parameters i.e. namely temperature, pH, turbidity, color, odor, taste, electric conductivity (EC), total dissolved solids (TDS), total hardness (Calcium + Magnesium), chloride, arsenic, phosphate, lead, ammonium ion, nitrite, Fecal coliform and Escherichia coli. Results exposed that all ground water samples of study area were grossly contaminated with pathogenic microorganisms like E. coli and Fecal coliform except one water sample that was obtained from community filter plant Samahni Chowk site. Besides it, values of some physicochemical water quality determining parameters also deviated from recommended limits of World Health Organization (WHO). Chloride ion concentration was little below the prescribed limits in almost all water samples. It has been proven that consumption of un-safe drinking water is one of the major cause of prevalence of water borne diseases like diarrhea, gastroenteritis, typhoid fever and malaria etc. in study area. Community water supply and sanitation projects should be encouraged; government should provide filter plants in all regions of the country so that people could have easy approach to safe drinking water.

Organochlorine pesticides (OCPs) pose a considerable threat to human and environmental health. Despite most OCPs have been banned, they are still reported to be used in developing countries, including Pakistan. We aimed to identify the distribution, origin, mobility, and potential risks from OCPs in three major environmental compartments, i.e., air, water, and soil, across Azad Jammu and Kashmir valley, Pakistan. The sums of OCPs ranged between 66 and 530 pg/g in soil, 5 and 13 pg/L in surface water, and 14 and 191 pg/m3 in air, respectively. The highest sum of OCPs was observed in the downstream zone of a river that was predominantly influenced by peri-urban and urban areas. The OCP isomers ratios (α-HCH/γ-HCH and o,p′-DDT/p,p′-DDT) indicate use of lindane and technical DDTs mixture as a source of HCH and DDT in the riverine environment. Similarly, the ratios of DDE and DDD/the sum of DDTs, α-endosulfan/β-endosulfan, and cis-chlordane/trans-chlordane indicate recent use of DDTs, endosulfan, and chlordane in the region. The air-water exchange fugacity ratios indicate net volatilization (fw/fa > 1) of α-endosulfan and trans-chlordane, and net deposition (fw/fa < 1) of β-endosulfan, α-HCH, γ-HCH p,p′-DDD, p,p′-DDE, and p,p′-DDT. Based on the risk quotient (RQ) method, we consider the acute ecological risks for fish associated with the levels of OCPs as negligible. However, more studies are recommended to evaluate the chronic ecological risks to other riverine-associated aquatic and terrestrial species as well as human health risks to the POPs exposure through food chain transfer in forthcoming years.

The emission of polychlorinated biphenyls (PCBs) in South Asian countries is one of the great environmental concerns and has resulted in the contamination of surrounding high altitude regions such as Azad Jammu and Kashmir (AJK), Pakistan. This first investigation of Polychlorinated Biphenyl (PCBs) concentrations in the ambient air, water and surface soil was conducted along the extensive stream network in the AJK valley of the Himalayan Region. In 2014, surface soil samples were taken and passive air and water samplers were deployed along the four main rivers, namely Jhelum, Neelum, Poonch and Kunhar, and analysed for PCBs (33 congeners) using GC-MS/MS. The ∑33PCBs concentrations ranged from 31.17 to 175.2 (mean ± SD: 81 ± 46.4 pg/L), ND to 1908 (1054 ± 588.5 pg/g), and 29.8 to 94.4 (52.9 ± 22.7 pg/m3) in surface water, soil and air matrices, respectively. The levels of dioxin-like PCBs (∑8DL-PCBs) contributed considerably towards the total PCBs concentrations: 60.63% (water), 43.87% (air) and 13.76% (soil). The log transformed air-water fugacity (log fa/fw) ratios ranged from -9.37 to 2.58; with 86.3% of the sampling sites showing net volatilization of selected PCB congeners. Similarly, the fugacity fractions for air-soil exchange exhibited narrow variation (0.8 to < 1) indicating net volatilization of PCBs. The ecological risk assessment showed low potential ecological risks (Eri  = 1.58-7.63) associated with PCB contamination. The present findings provide baseline data that suggest cold trapping of POPs in the remote mountainous areas of Pakistan and can support environmental management of POPs at the regional level. This pioneer investigation campaign to assess the PCBs concentrations in Himalayan Riverine Network of Azad Jammu and Kashmir, Pakistan helps to develop baseline data of PCBs from the strategically important riverine environment that would help in future regional as well as global ecological studies. However, the effects of temperature variations on the sampling rates of chemicals across a wide spectrum of volatility along the elevation gradient were not taken under consideration for PCBs atmospheric concentrations.

Arsenic-contaminated aquifers are currently estimated to affect ~150 million people around the world. However, the full extent of the problem remains elusive. This is also the case in Pakistan, where previous studies focused on isolated areas. Using a new data set of nearly 1200 groundwater quality samples throughout Pakistan, we have created state-of-the-art hazard and risk maps of arsenic-contaminated groundwater for thresholds of 10 and 50 μg/liter. Logistic regression analysis was used with 1000 iterations, where surface slope, geology, and soil parameters were major predictor variables. The hazard model indicates that much of the Indus Plain is likely to have elevated arsenic concentrations, although the rest of the country is mostly safe. Unlike other arsenic-contaminated areas of Asia, the arsenic release process in the arid Indus Plain appears to be dominated by elevated-pH dissolution, resulting from alkaline topsoil and extensive irrigation of unconfined aquifers, although pockets of reductive dissolution are also present. We estimate that approximately 50 million to 60 million people use groundwater within the area at risk, with hot spots around Lahore and Hyderabad. This number is alarmingly high and demonstrates the urgent need for verification and testing of all drinking water wells in the Indus Plain, followed by appropriate mitigation measures.

Persistent organic pollutants (POPs) persisting in the environment, which accumulate in human and animal tissue and bio-magnify in food-chains, would have significant impacts on human health and the environment. Thus, the present study was designed to investigate the accumulation of organic pollutants in prawn from streams of Sialkot, Pakistan. Fresh water prawn Macrobrachium lamarrei was captured from streams of study area. Samples were prepared for extraction of selected organic pollutants and then analyzed through gas chromatograph-electron capture detector (GC-ECD). Results of current study showed that five pesticide residues, i.e., B-HCH, Lindane, DDD, 2, 4-DDT and 4, 4-DDT were detected in composite prawn sample. The rest of POPs residues were not found in prawn. The ratio of α-HCH/γ-HCH indicated an input of technical HCH and long range transport, while the ratio of DDT/(DDD + DDE) showed recent use of DDT to the study area. The high values of TEC-HQ and PEC-HQ of POPs in the studied prawn samples depicted risk posed to health.

This study aims to assess the spatial patterns of selected dust-borne trace elements alongside the river Indus Pakistan, their relation with anthropogenic and natural sources, and the potential risk posed to human health. The studied elements were found in descending concentrations: Mn, Zn, Pb, Cu, Ni, Cr, Co, and Cd. The Index of Geo-accumulation indicated that pollution of trace metals were higher in lower Indus plains than on mountain areas. In general, the toxic elements Cr, Mn, Co and Ni exhibited altitudinal trends (P < 0.05). The few exceptions to this trend were the higher values for all studied elements from the northern wet mountainous zone (low lying Himalaya). Spatial PCA/FA highlighted that the sources of different trace elements were zone specific, thus pointing to both geological influences and anthropogenic activities. The Hazard Index for Co and for Mn in children exceeded the value of 1 only in the riverine delta zone and in the southern low lying zone, whereas the Hazard Index for Pb was above the bench mark for both children and adults (with few exceptions) in all regions, thus indicating potential non-carcinogenic health risks. These results will contribute towards the environmental management of trace metal(s) with potential risk for human health throughout Pakistan.

The present study aims to assess the arsenic (As) levels into dust samples and its implications for human health, of four ecological zones of Pakistan, which included northern frozen mountains (FMZ), lower Himalyian wet mountains (WMZ), alluvial riverine plains (ARZ), and low lying agricultural areas (LLZ). Human nail samples (N=180) of general population were also collected from the similar areas and all the samples were analysed by using ICP-MS. In general the higher levels (p<0.05) in paired dust and human nail samples were observed from ARZ and LLZ than those of other mountainous areas (i.e., WMZ and FMZ), respectively. Current results suggested that elevated As concentrations were associated to both natural, (e.g. geogenic influences) and anthropogenic sources. Linear regression model values indicated that As levels into dust samples were associated with altitude (r(2)=0.23), soil carbonate carbon density (SCC; r(2)=0.33), and population density (PD; r(2)=0.25). The relationship of paired dust and nail samples was also investigated and associations were found for As-nail and soil organic carbon density (SOC; r(2)=0.49) and SCC (r(2)=0.19) in each studied zone, evidencing the dust exposure as an important source of arsenic contamination in Pakistan. Risk estimation reflected higher hazard index (HI) values of non-carcinogenic risk (HI>1) for children populations in all areas (except FMZ), and for adults in LLZ (0.74) and ARZ (0.55), suggesting that caution should be paid about the dust exposure. Similarly, carcinogenic risk assessment also highlighted potential threats to the residents of LLZ and ARZ, as in few cases (5-10%) the values exceeded the range of US-EPA threshold limits (10(-6)-10(-4)).

Contamination of groundwater due to heavy metals is one of the most important concerns that have received attention at regional, local and global levels because of their toxicological importance in ecosystems and impact on public health. The present study was designed to assess the quality of groundwater in relation to heavy metal pollution and its implication on human health. The groundwater quality of Sialkot, an industrial city of Pakistan, was evaluated using water samples collected from 25 localities during October-November 2005. Twenty-two physiochemical parameters including pH, Electric Conductivity (EC), Total Dissolved Solids (TDS), Salinity, Temperature, Turbidity, Sulfate (SO4) Chloride (Cl), Total Hardness, Iodide, Fluoride, Ferric (Fe+3), Nitrate (NO3), Manganese (Mn), Total Chlorine, Alkalinity, Zinc (Zn), Lead (Pb), Iron (Fe), Copper (Cu), Nickel (Ni) and Chromium (Cr) were recorded. The results were compared with standard guidelines of World Health Organization (WHO) and Pakistan Standard Quality Control Authority (PSQCA) for groundwater quality. Cluster Analysis (CA) grouped all sites into four zones based on spatial similarities and dissimilarities of physiochemical properties. Zone 1 was highly ontaminated with high level of turbidity; EC, TDS, SO4, Cl, total hardiness, Zn, Pb and Fe concentrations were above the permissible levels of WHO and PSQCA. Cr+6 was detected in nineteen sampling sites and its concentration ranged between 0.01 - 0.30 mg/L. Factor Analysis (FA) and Discriminant Analysis (DA) revealed significant variables including pH, EC, TDS, SO4, NO3, Cl, Total Hardness, Iodide, Total Chlorine, Fluoride, alkalinity, Pb, Fe and Mn which are responsible for variations in groundwater quality and affect water chemistry. The results revealed that the groundwater of the study area cannot be considered of good quality as it is highly turbid (57% of total sites) with high level of Zn, Fe and Pb, which were above WHO and PSQCA permissible limits. The spatial distribution maps of water quality parameters were produced using Geographic Information System (GIS). The distribution maps served as important information to understand ecological status of the groundwater systems and for the identification of groundwater quality parameters withconcentration above the allowable limits of WHO and to fin d out potential areas where water treatment plants/technologies can be targeted in Sialkot.