Mujtaba Baqar

Persistent organic pollutants in Pakistan: Potential threat to ecological integrities in terms of genotoxicity and oxidative stress

ABSTRACT As a consequence of both increasing population and industrialization in agro-economic sector, Pakistan has inevitably been confronted by multicomplex environmental challenges. Owing in part to poor regulatory framework, pollution due to persistent organic pollutants (POPs) has caused serious problems throughout the country. Resultantly, extensive use of POPs is causing vigorous deterioration of environment and human health. The current study addresses: (1) the general information on associated ecological effects and toxicity assessment by meta-analysis for local fauna and flora (2) their respective occurrence in living organisms; and (3) sources and distribution patterns of various POPs classes in environmental compartments of Pakistan. Based on the study, it can be concluded that the environment of Pakistan is highly contaminated with organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP), and polychlorinated naphthalenes (PCNs), which is further supported with the meta-analysis. Nevertheless, unavailability of environmental quality standards and food safety for POPs render it a forthcoming challenge of multicompartment toxicity exposure. Therefore, strategies must be planned for risk assessment of biologically active POPs, while the POP waste inventory should be elevated, along with the necessary measures to promote appropriate handling and treatment of POP as a matter of prime importance.

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

ABSTRACT 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.

Impact of biochar and compost amendment on soil quality, growth and yield of a replanted apple orchard in a four-year field study: Impact of biochar and compost amendment on soil quality, growth and yield of a replanted apple orchard in a four-year field study

BACKGROUND Numerous studies have addressed the positive effects of organic amendments on soil and plant productivity under short-term field studies. However, to date, few studies have been conducted on the effects of organic amendment on the orchards where high nutrient bioavailability is required. This study deals with the effects of biochar and compost on soil quality, growth and yield of a replanted apple orchard in the northeast of Iran. RESULTS Biochar+compost application resulted in 37% and 300% higher soil total organic carbon and available phosphorus content, respectively, during the first 3 years of experimentation compared to control. Similarly, trunk diameter and shoot number of apple trees increased 23-26% by the end of the first year. Nevertheless, there were no significant changes in fruitfulness, fruit weight or starch pattern index as productivity indices. CONCLUSION Biochar and compost were beneficial in improving soil quality, mainly by increasing soil nutrient content and decreasing soil bulk density, and in increasing plant growth at early growth stages of apple orchards. However, they failed to enhance overall yield and fruit quality, most likely due to their limited ability to suppress apple replant disease.

Organochlorine contaminants in freshwater mussels; occurrence, bioaccumulation pattern, spatio-temporal distribution and human health risk assessment from the tributaries of River Ravi, Pakistan

ABSTRACT The present study was conducted to investigate the bioavailable levels and human health risk of organochlorine contaminants (OCs), particularly organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in freshwater mussels from northern three tributaries of River Ravi, Pakistan that provides the pioneer data for the occurrence of POPs in the freshwater mussels from Pakistan. The Σ23OCPs and Σ35PCBs concentrations in mussels were ranged from 189.66–2049.40 ng/g and 25.81 to 135.38 ng/g, respectively. The comparison of current bioavailable levels of OCs with maximum residual limits (MRLs) established by Food and Agricultural Organization and European Union revealed that Σendosulfan (100%), ΣDDTs (93%), HCB (87%), β-HCH (77%), endrin (77%), γ-HCH (70%), heptachlor (67%), aldrin (67%), dielrin (67%), Chlordane (70%), α-HCH (40%), and WHO-TEQ (2005) values for PCB-126, PCB-169 and Σ8DL-PCBs were exceeding the permissible limits. The human health risk assessment revealed the occurrence of substantial lifetime carcinogenic risk for OCPs and PCBs at both 50th and 95th percentile concentrations in freshwater mussels from the tributaries of River Ravi. Therefore, the freshwater mussels are recommended to be used in environmental toxicological studies to assess the bioavailable levels of pollution in hostile environment.

Human Health Risk Surveillance Through the Determination of Organochlorine Pesticides by High-Performance Liquid Chromatography in Water, Sediments, and Fish from the Chenab River, Pakistan

ABSTRACT The current study assessed the spatiotemporal variations and human health surveillance associated with organochlorine pesticide (OCP) contamination in water, sediments, and fish from Chenab River, Pakistan. The OCP determinations were performed using high-performance liquid chromatography with a reverse-phase C18 column. The total OCP levels ranged from 13.33 to 274.59 ng/L in water, 4.63 to 239.11 ng/g in sediments, and 23.79 to 387.12 ng/g in fish species. The overall pattern of mean OCP concentrations followed the order as ΣDDTs > Σendosulfan > aldrin and OCP pollution pattern among the headworks were Khanki Barrage > Qadirabad Barrage > Trimmu Barrage > Marala Barrage in all three environmental matrixes during both seasons. The estimated daily intake (EDI) for ∑OCPs was found to be 22.44 ng/kg/day. The hazard ratios calculated to assess the carcinogenic risk indicated that the values for ∑DDT and aldrin at the 95th percentile concentrations were greater than one, indicating the probability of carcinogenic risk occurrence of one in million populations due to fish consumption. Therefore, these high levels of OCPs and carcinogenic risk through fish consumption highlight the needs of immediate elimination of OCPs from riverine environment of Chenab River and we recommend long-term monitoring-based freshwater ecological studies to be conducted in the study area.

Noise pollution in the hospital environment of a developing country: A case study of Lahore (Pakistan)

ABSTRACT The present study investigates the noise pollution levels in public- and private-sector hospitals of Lahore. The noise pollution parameters were investigated from 20 public and 10 private hospitals. We observed that the equivalent continuous sound level (Leq) values varied significantly in different departments of the hospitals as well as at different times of the day. The public-sector hospitals had significantly higher noise pollution compared to the private-sector hospitals. The Wilcoxon Mann-Whitney two-sample rank-sum test revealed significant difference between noise levels in intensive care unit (ICU) during morning and in emergency, waiting area, intensive care unit (ICU), and reception during daytimes. However, no significant differences were found for any department during the evening. The Leq values were found to be higher than the international norms (WHO standards) for all hospitals, higher than USEPA for 29 hospitals and higher than local standards for 27 hospitals. Overall, significantly lower sound levels were always observed in private hospitals.

Use of Mercury in Dental Silver Amalgam: An Occupational and Environmental Assessment

The objective of this study was to assess the occupational exposure to mercury in dentistry and associated environmental emission in wastewater of Lahore, Pakistan. A total of ninety-eight blood samples were collected comprising 37 dentists, 31 dental assistants, and 30 controls. Results demonstrate that the dentistry personnel contained significantly higher mean concentration of mercury in their blood samples (dentists: 29.835 µg/L and dental assistants: 22.798 µg/L) compared to that of the controls (3.2769 µg/L). The mean concentration of mercury was found maximum in the blood samples of older age group (62.8 µg/L) in dentists and (44.3 µg/L) in dental assistants. The comparison of mercury concentration among dentists, dental assistants, and controls (pairing based on their ages) revealed that the concentration increased with the age and experience among the dentists and dental assistants. Moreover, the mercury concentration in all the studied dental wastewater samples, collected from twenty-two dental clinics, was found to be exceeding the recommended discharge limit of 0.01 mg/L. Therefore, we recommend that immediate steps must be taken to ensure appropriate preventive measures to avoid mercury vapors in order to prevent potential health hazards to dentistry personnel. Strong regulatory and administrative measures are needed to deal with mercury pollution on emergency basis.