DSpace Collection: Environmental Science Department

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

2024-12-09T08:52:08Z

Title: Gaseous and soil OCPs and PCBs along the Indus River, Pakistan: spatial patterns and air–soil gradients Authors: Ilyas, Dr. Shazia; Sohail, Muhammad; Eqani, Syed Ali Musstjab Akber Shah; Bokhari, Habib; Ali, Nadeem; Podgorski, Joel E.; Muhammad, Shafi; Adelman, Dave; Lohmann, Rainer Abstract: 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 < 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 > 0.05) for the air samples, while PCB concentrations were significantly higher (p < 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.

Impact of Land Uses on Drinking Water Quality in Selected Areas of Lahore City

2024-12-09T08:59:57Z

Title: Impact of Land Uses on Drinking Water Quality in Selected Areas of Lahore City Authors: Masood, Sanwal; Ahmed, Dildar; Machado, Silvia Manuela Marinho; Aslam, Dr. Sohaib Abstract: The biggest threat to the quality of rapidly diminishing groundwater resources is the uncontrolled pollution by different human activities such as industries, sewage/wastewater drains, and agricultural practices. In the present study, water samples were collected and analyzed for selected physicochemical parameters including toxic metals for determining the impact of land uses on the ground water quality of Lahore, Pakistan. Our results showed that water of three sites namely Shadman, Samnabad and Township had the TDS above 300 mgL-1 and this value was comparatively greater than samples of other areas. Only one site named Ravi Town showed the extremely low concentration of DO i.e. 1.6 mgL-1. All the heavy metals values were within the permissible limit as per world health organization (WHO) guidelines except for iron and silver. However, significant differences were present among the water samples of selected locations which indicated strong influence of type of land use on ground water quality. Monitoring of such activities by government departments is the deer need for conserving the quality of drinking water of this mega city

Assessment of heavy metals and associated oxidative stress in occupationally exposed workers from Bannu and Karak Districts in Pakistan

2024-12-19T20:03:20Z

Title: Assessment of heavy metals and associated oxidative stress in occupationally exposed workers from Bannu and Karak Districts in Pakistan Authors: Khan, Kaleem; Muhammad Rafq, Tariq; ‑Ur‑Rahim Bacha, Aziz; Nabi, Iqra; Muhammad, Irshad; Faridullah, Faridullah; Younis, Dr. Muhammad; Muhammad Khan, Daud; Aziz, Rukhsanda; Muhammad, Amin; Arifeen, Awais; Aslam, Dr. Sohaib; Ahmad, Shabir; Iqbal, Akhtar Abstract: Heavy metals (HMs) are extensively found in occupationally exposed miners and indus trial workers, which may cause serious health-related problems to the large workforce. In order to evaluate the impact of these toxic pollutants, we have inves tigated the efect of cadmium (Cd), chromium (Cr), copper (Cu), and lead (Pb) concentration on exposed workers of mining, and woolen textile mill and com pared the fndings with unexposed individuals. From each category like exposed workers (mining, and woolen mill textile site) and unexposed individuals, 50 blood samples were taken. The occurrence of HMs in a sample was investigated through atomic absorp tion spectrometry while the oxidative stress marker malondialdehyde (MDA) and antioxidant enzyme statuses such as superoxide dismutase (SOD) and catalase (CAT) were analyzed in exposed and control samples. The results showed signifcant (p<0.05) variation in Cd, Cr, Cu, and Pb levels in exposed and control samples. The concentration of Cd in the blood of WMWs, KMWs, and control group was 5.75, 3.89, and 0.42 μg/dL, respectively. On the other hand, the concentration of Pb in the blood of WMWs, MWs, and control was 32.34, 24.39, and 0.39 µg/dL while the concentrations of Cr and Cu in the blood of WMWs, MWs, and control group were 11.61 and 104.14 μg/dL, 4.21 and 113.21 μg/dL, 0.32 and 65.53 μg/dL, respectively. An increase in MDA was recorded in the exposed workers’ group as compared to control subjects, whereas SOD and CAT activities decreased. Meanwhile, MDA was signifcantly and positively (p<0.01) correlated with HMs, while neg ative signifcant correlations were found among HMs with SOD and CAT

Rain regime and soil type affect the C and N dynamics in soil columns that are covered with mixed-species mulches

2024-12-09T09:00:50Z

Title: Rain regime and soil type affect the C and N dynamics in soil columns that are covered with mixed-species mulches Authors: Iqbal, Akhtar; Aslam, Dr. Sohaib; Alavoine, Gonzague; Benoit, Pierre; Garnier, Patricia; Recous, Sylvie Abstract: Aims The role of precipitation on the decomposition of residue mulches is of primary importance for the ade quate management of nutrients in no-tilled agrosystems. The objective of this work was to understand the inter actions between water dynamics and crop residue qual ity and their effect on carbon (C) and nitrogen (N) mineralization. Methods The decomposition of two residue mixtures (wheat + alfalfa and maize + lablab) left at the surface of repacked soil columns, was studied under controlled con ditions, at 20 °C over 84 days. Simulated rain pulses were either light and frequent or heavy and infrequent. A loamy soil (Luvisol) and a sandy soil (Ferralsol) were used. Results The maize/lablab mulch remained wetter be tween rain pulses which induced greater decomposition than the wheat/alfalfa mulch. Frequent/light rain pulses maintained the mulches wetter between pulses than infrequent/heavy rain pulses, and therefore these mulches decomposed faster. The loamy soil favored the moistening of the mulch layer in contact with the soil which enhanced its decomposition, compared to the sandy soil. Conclusions The water dynamics (water content of the mulches and soil, evaporation, and drainage) was highly modified by residue quality, rain regime and soil type, which in turn significantly affected the mineralization of C and N.