Trends of climate change in the lower Indus Basin region of Pakistan : future implications for agriculture

Purpose - Lower Indus Basin (LIB) region is the food basket of Pakistan, and climatic variation in response to global warming might severely affect the crop production and, thus, food security and ultimately to the economy of the country. Design/methodology/approach - The authors analyzed the previous climatic factors data series of LIB region to investigate the past and present climatic trends and to predict the future changes. Climatic changes were monitored by studying temperature, rainfall and relative humidity (RH) dynamics at two locations (Lahore and Multan) of the LIB region, Pakistan, by using data from 1953 to 2006. The data were divided into two equal halves (1953-1979 and 1980-2006) and statistically compared for the aforementioned weather parameters. Findings - The results suggested that mean minimum temperature (MMT) and overall mean temperature in winter were significantly increased, whereas few summer months had also experienced the reduction in both temperatures. However, few minor changes were also observed for the mean maximum temperature at both locations. The rainfall amount did not vary significantly at both locations, with the exception for the months of February and June at Lahore location, which experienced relatively higher rainfall in latter period (1980-2006). However, morning and evening RH was significantly increased at Multan throughout the year and for some selected months (February-March and May-July) at Lahore. However, the comparison of climatic data of both temporal halves suggested either dryer weather during winter months because of increase in MMT and/or increase in area under irrigated agriculture, resulting in more evaporation at both locations. Similarly, the data also indicated the early monsoon rainfall patterns in summer and late western depression rainfall spell during winter, which played key role to affect the crop yield because of irregular rain events. Research limitations/implications - The current manuscript would be very useful for the disaster management authorities and agriculture sector to predict the future irregular trends of climate change in Pakistan. Moreover, current findings can be important tool toward the management of climatic changes issues (i.e. floods and dryer spells) and to formulate the future strategies for the improved crop growth in arid and/or semi-arid developing nations such as Pakistan. Originality/value - The current manuscript, for the very first time, provided detailed insights into key climatic factors changes for past seven decades, into the severely climate change-affected areas of the world. Furthermore, agricultural sector is likely to be severely affected because of minor seasonal change in temperature and moisture, and have a strong food security impact, which can be reflected with current data set to cope with both ecological and economic impacts of climate change in Pakistan. The current findings would be useful to manage the climate change-related issues in Pakistan, including the social, environmental and economic

Molecularly Tracing of Children Exposure Pathways to Environmental Persistent Organic Pollutants and the Autism Spectrum Disorder Risk

Organic pollutants (OPs) including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs) have showed neuro-damaging effects, but studies concerning the autism spectrum disorder (ASD) risk are limited. A case-control study with ASD (n=125) and healthy control (n=125) children was conducted on the different land use settings across Punjab, Pakistan. Serum concentrations of 26 OCPs, 29 PCB congeners, 11 PBDEs and 32 PAHs were measured. Serum PCB77 (AOR = 2.00; 95% CI: 1.43, 2.18), PCB118 (AOR = 1.49; 95% CI: 1.00, 2.00), PCB128 (AOR = 1.65; 95% CI: 1.01, 1.91), PCB153 (AOR = 1.80; 95% CI: 1.55, 1.93) were significantly higher, but PCB187 (AOR = 0.37; 95% CI: 0.24, 0.49) was significantly lower in the ASD cases when compared to the controls. Serum BDE99 (AOR = 0.48; 95% CI: 0.26, 0.89) was significantly higher in the healthy controls than in the ASD cases. Among the analysed OCPs, p,p′-DDE (AOR = 1.50; 95% CI: 1.00, 1.85) was significantly elevated in the ASD cases with comparison in the controls. For PAHs, serum dibenzothiophene (AOR = 7.30; 95% CI: 1.49, 35.85) was significantly higher in the ASD, while perylene (AOR = 0.25; 95% CI: 0.06, 1.10) and fluorene (AOR = 0.21; 95% CI: 0.06, 0.72) were significantly higher in the controls. In addition, many of the serum pollutants were significantly associated with GSTT1, GSTM1 (null/present polymorphism) and presented the genotypic variation to respond xenobiotics in children. The children living in proximity to urban and industrial areas had a greater exposure to most of the studied pollutants when compared to the rural children, however children residing in rural areas showed higher exposure to OCPs. This comprehensive study documents an association between environmental exposure risk of several organic pollutants (OPs) from some contaminated environmental settings with ASD risk in children from Pakistan

Gaseous and soil OCPs and PCBs along the Indus River, Pakistan: spatial patterns and air–soil gradients

This study presents first-hand information on the occurrence of persistent organic pollutants (POPs) in the ambient air and surface soil along the Indus flood-plain, Pakistan. The sampling campaign was conducted at 15 site locations during 2014–15, along the Indus River (approximately 1300 km). Composite surface soil samples (N = 15) and passive air samples (N = 15) were collected for the estimation of gaseous POPs as well as air–soil exchange to evaluate the POP emission and distribution or dispersion patterns, source tracking, and contribution of the local and regional sources towards POP accumulation in the Indus River system. Among the studied POPs, levels of DDTs and PCBs were noticeably higher in ambient air (50–560 and 10–1100 pg m−3) and in soil (0.20–350 and 1.40–20 ng g−1), respectively. Regarding the spatial patterns, higher DDT concentrations (ng g−1) were detected in the air and soil samples collected from the wet mountain zone (WMZ) (p \u3c 0.05), followed by the alluvial riverine zone (ARZ), low-lying mountain zone (LLZ), and frozen mountain zone (FMZ). The PCB data did not exhibit significant differences (p \u3e 0.05) for the air samples, while PCB concentrations were significantly higher (p \u3c 0.05) in soil from the LLZ, which may be associated with rapid urbanization and industrial activities in this area. The air–soil exchange of DDTs and PCBs showed net volatilization at most of the studied sites except for a few samples from the FMZ and WMZ. Results of this study about air–soil exchange gradients indicate the long range regional atmospheric transport (LRAT) of POPs to the colder areas (FMZ) of Pakistan, where these act as a secondary source of POPs in these areas

Freely dissolved Organochlorine Pesticides (OCPs) and Polychlorinated Biphenyls (PCBs) along the Indus River Pakistan: Spatial pattern and Risk assessment

Freely dissolved OCPs and PCBs were measured by using polyethylene passive samplers at 15 sites during 2014 throughout the stretch of the Indus River to investigate the spatial pattern and risk assess. Levels (pg/L) of dissolved ∑OCPs and ∑PCBs ranged from 34 to 1600 and from 3 to 230. Among the detected OCPs, dissolved DDTs (p,p′-DDE, followed by p,p′-DDT) predominated with levels of 0.48 to 220 pg/L. The order of occurrence for other studied OCPs was as follows: HCB, endosulfans, chlordanes, and HCHs. Spatially, dissolved (pg/L) ∑OCPs varied (p \u3c 0.05) as the following: surface water of the alluvial riverine zone (ARZ) showed the highest levels (114) followed by the frozen mountain zone (FMZ) (52.9), low-lying zone (LLZ) (28.73), and wet mountain zone (WMZ) (14.43), respectively. However, our zone-wise PCB data did not exhibit significant differences (p \u3e 0.05). Principal component analysis/multilinear regression results showed pesticide usage in the crop/orchard fields and health sector, electric and electronic materials, and widespread industrial activities as the main source of OCPs and PCBs along the Indus River. Our results showed that OCPs and PCBs contaminated water intake, playing an important role towards the considerable cancer/non-cancer risk (HI and CR values) along the Indus River Flood-Plain

Soil phosphorus fractionation as a tool for monitoring dust phosphorus signature underneath a Blue Pine (Pinus wallichiana) canopy in a Temperate Forest

Aims of the study: This study aims (i) to monitor the amount of dust deposition during dry season in the moist temperate forest; (ii) to study nature of P fractions in the dust samples falling on the trees in the region; (iii) to study soil P fractions as influenced by the processes of throughfall and stemflow of a Blue Pine (Pinus wallichiana) canopy and to finger print the contribution of dust towards P input in the temperate forest ecosystem.Area of study: The site used for the collection of soil samples was situated at an elevation of 6900 feet above sea levels (temperate forest in Himalaya region) in the Thandani area national forest located in the north west of Pakistan.Material and methods:  For soil sampling and processing, three forest sites with three old tree plants per site were selected at approximately leveled plain for surface soil sampling. Two dust samples were collected and analyzed for different physicochemical properties along with different P fractions. First dust sample was collected from a site situated at an elevation of 4000 feet and second one was collected from an elevation of 6500 feet above sea levels. Modified Hedley procedure for the fractionation of P in the dust and soil samples were used.Main results: The input of dust was 43 and 20 kg ha-1 during drier months of the year (September-June) at lower and higher elevation sites respectively, and the dust from lower elevation site had relative more all P fractions than the other dust sample. However, HCl-Pi fraction was dominant in both samples. Both labile (water plus NaHCO3) and non-labile (NaOH plus HCl) inorganic P (Pi) fractions were significantly increased in the surface soil by both stemflow and throughfall compared to the open field soil. The buildup of NaOH and HCl-Pi pools in soils underneath the canopy might prove useful in fingerprinting the contribution of atmospheric dust towards P cycling in this temperate forest.Research highlights: The role of dust in the cycling of P in temperate forest in Himalaya region.Keywords: soil phosphorus fractions; atmospheric dust; stemflow, throughfall; temperate forest

Distribution and risk assessment of organochlorine contaminants in surface water from River Chenab, Pakistan

Concentrations in surface waters (including particulate phase) of the River Chenab ranged from 27-1100 ng L-1 and 25-1200 ng L-1 for OCPs and 7.7-110 ng L-1 and 13-99 ng L-1 for PCBs during summer and winter, respectively from 2007-2009. DDTs exhibited the highest concentration, followed by HCHs > chlordane > [summation operator]24PCBs > [summation operator]other OCPs. Different indicative ratios for organochlorines suggest that current use, long range transport and also past application of these chemicals contribute to the total burden. Statistical analysis highlighted agricultural and industrial activities and municipal waste disposal as main sources of OCPs and PCBs in the riverine ecosystem of the River Chenab. Risk Quotients (RQCCCs) > 10 for DDTs and PCBs levels in collected water samples from the River Chenab suggest that risk from DDTs and PCBs is moderate to severe and fluxes calculated for OCPs and PCBs from the River Chenab to the Indus River were 7.5 tons per year and 1.0 tons per year, respectively