The Western Himalayan fir tree ring record of soil moisture in Pakistan since 1855.

Data on historical soil moisture is crucial for assessing and responding to droughts that commonly occur in climate change-affected countries. The Himalayan temperate forests in Pakistan are particularly at risk of climate change. Developing nations lack the means to gather surface soil moisture (SSM) information. Tree rings are one way to bridge this gap. Here, we employed dendrochronological methods on climate-sensitive tree rings from Abies pindrow to reconstruct the SSM in the Western Himalayan mountain region of Pakistan from 1855 to 2020. December (r = 0.41), May (r = 0.40), and June (r = 0.65) SSMs were found to be the limiting factors for A. pindrow growth. However, only the June SSM showed reconstruction possibility (coefficient of efficiency = 0.201 and reduction of error = 0.325). Over the studied period, we found 6 years (wet year) when June SSM was above the threshold of 32.04 (mean + 2 δ) and 1 year (dry year) when June SSM was below the threshold of 21.28 (mean - 2 δ). It was revealed that 1921 and 1917 were the driest and wettest SSM of all time, with means of 19.34 and 36.49, respectively. Our study shows that winter soil moisture is critical for the growing season in the context of climate change. Climate change has broad impacts on tree growth in the Western Himalayas. This study will assist various stakeholders in understanding and managing local and regional climate change.

Composition, impacts, and removal of liquid petroleum waste through bioremediation as an alternative clean-up technology: A review.

Exposure to hazardous wastes, especially petroleum wastes hydrocarbon (PWHCs), can damage human health and biological diversity. A huge amount of petroleum waste along with persistent organic pollutants is being generated during exploration and processing of crude oil. The dumping of petroleum waste hydrocarbons in an open pit contaminates the soil which can cause severe threats to human health and agro-geo-environmental ecosystem. The current study aimed to evaluate the mode of occurrence, composition, environmental, and health impacts of petroleum waste by using recent literature. The extracted results show that oil emulsion contains 48% oil, suspension 23%, settled emulsion 42%, and sludge emulsion 36%. The study discusses the possible biological techniques for rehabilitation of petroleum waste-contaminated areas. Several physical and chemical techniques are available for remediation of petroleum waste, but they are either costly or environmentally not feasible. Whereas, biological remediation namely, Bioremediation (Biostimulation and Bioaugmentation), Phytoremediation (Phytodegradation, Rhizoremediation, Phytovolatilization, and Rhizo-filtration) is a cheap and environmentally friendly way to remove petroleum waste hydrocarbons from contaminated soil and water. Some important enzymes (i.e., peroxidase, nitrilase, nitroreductase, phosphatase) and plant species i.e., Acacia and Chloris species are prominent methods to remediate the PWHCs. The knowledge assembled in this review is expected to create new doors for researchers to develop more efficient techniques to control the harmful impacts of PWHCs on the environment and health.

Comparative Analysis of Microbial Consortiums and Nanoparticles for Rehabilitating Petroleum Waste Contaminated Soils.

Nano-bioremediation application is an ecologically and environmentally friendly technique to overcome the catastrophic situation in soil because of petroleum waste contamination. We evaluated the efficiency of oil-degrading bacterial consortium and silver nanoparticles (AgNPs) with or without fertilizer to remediate soils collected from petroleum waste contaminated oil fields. Physicochemical characteristics of control soil and petroleum contaminated soils were assessed. Four oil-degrading strains, namely Bacillus pumilus (KY010576), Exiguobacteriaum aurantiacum (KY010578), Lysinibacillus fusiformis (KY010586), and Pseudomonas putida (KX580766), were selected based on their in vitrohydrocarbon-degrading efficiency. In a lab experiment, contaminated soils were treated alone and with combined amendments of the bacterial consortium, AgNPs, and fertilizers (ammonium nitrate and diammonium phosphate). We detected the degradation rate of total petroleum hydrocarbons (TPHs) of the soil samples with GC-FID at different intervals of the incubation period (0, 5, 20, 60, 240 days). The bacterial population (CFU/g) was also monitored during the entire period of incubation. The results showed that 70% more TPH was degraded with a consortium with their sole application in 20 days of incubation. There was a positive correlation between TPH degradation and the 100-fold increase in bacterial population in contaminated soils. This study revealed that bacterial consortiums alone showed the maximum increase in the degradation of TPHs at 20 days. The application of nanoparticles and fertilizer has non-significant effects on the consortium degradation potential. Moreover, fertilizer alone or in combination with AgNPs and consortium slows the rate of degradation of TPHs over a short period. Still, it subsequently accelerates the rate of degradation of TPHs, and a negligible amount remains at the end of the incubation period.

Impacts of the linear flowing industrial wastewater on the groundwater quality and human health in Swabi, Pakistan.

The present study aimed to probe the extent and mobility of contamination in wastewater and its impact on groundwater and human health in the Swabi region in Pakistan. Representative samples (n = 86) were collected from both wastewater streams and groundwater in an analogous environmental setting. The result showed that pH, color, hardness, alkalinity, chemical oxygen demand, chloride, suspended solids, total dissolved solids, Cr, Cd, Pb, Cu, Fe, Mg, Na, Ca, and K in industrial wastewater were higher than the Pak-EPA (Pakistan Environmental Protection Agency) and the United State Environmental Protection Agency (US-EPA) devised standards. In groundwater, the concentration (µg L-1) of trace elements, namely, Cd (1.16), Pb (17.4), Fe (12426), Mn (320), Mg (129784), Na (33630), Ca (177944), and K (9558) was significantly higher than the WHO (World Health Organization) acceptable level, showing decreasing tendency with increasing distance from the industrial zone. The study perceived that wastewater caused permanent hardness, while groundwater hardness was decreased from permanent to temporary at a distance from industries. Integrated health risk assessment revealed that Cu, Zn, and Co may cause low risk, Na, Mn, Ni, Pb, and Cr cause medium risk, whereas Cd, Fe, Mg, Ca, and K may cause a high health risk. Moreover, the average daily intake of Fe, Mn, Mg, Na, Ca, and K was comparably higher than Cr, Cd, Pb, Ni, Cu, Zn, and Co in both adults and children. The mode of occurrence of contaminants in groundwater was due to the leaching of contaminated wastewater and the oxidation of metals. Furthermore, carbonates, chloride, and SAR (sodium adsorption ratio) precipitation have a key role in groundwater contamination and influencing the natural water quality. The study concluded that the health problems in the surrounding areas were due to the use of contaminated water for drinking and household purpose. The study suggests filtering the drinking water and treating the wastewater before releasing it into the environment.