M. Tahir Shah

Soil and vegetables enrichment with heavy metals from geological sources in Gilgit, northern Pakistan.

This study was conducted to investigate the concentrations of heavy metals in soil and vegetables, and human health risks through ingestion of contaminated vegetables. Soil and vegetable samples were collected from different locations in Gilgit, northern Pakistan, and analyzed for Cd, Cu, Ni, Pb and Zn. Plant transfer factors (PTF), daily intake of metals (DIM) and health risk index (HRI) were also calculated. The concentrations of Cd, Cu and Zn exceeded their respective permissible limits in soil samples. The highest concentrations of Cu, Ni, Pb and Zn were observed in the edible parts of Malva neglecta, Brassica oleracea, Mintha sylvestris and Brassica campestris, respectively. PTF values were lower for all the selected heavy metals, except for Cd. Furthermore, the HRI values were within the safe limit (<1) except for Pb; therefore, the health risks of metals through ingestion of vegetables were of great concern in the study area.

Use of constructed wetland for the removal of heavy metals from industrial wastewater

This study was conducted to investigate the effectiveness of a continuous free surface flow wetland for removal of heavy metals from industrial wastewater, in Gadoon Amazai Industrial Estate (GAIE), Swabi, Pakistan. Industrial wastewater samples were collected from the in-let, out-let and all cells of the constructed wetland (CW) and analyzed for heavy metals such as lead (Pb), cadmium (Cd), iron (Fe), nickel (Ni), chromium (Cr) and copper (Cu) using standard methods. Similarly, samples of aquatic macrophytes and sediments were also analyzed for selected heavy metals. Results indicate that the removal efficiencies of the CW for Pb, Cd, Fe, Ni, Cr, and Cu were 50%, 91.9%, 74.1%, 40.9%, 89%, and 48.3%, respectively. Furthermore, the performance of the CW was efficient enough to remove the heavy metals, particularly Cd, Fe, and Cu, from the industrial wastewater fed to it. However, it is suggested that the metal removal efficiency of the CW can be further enhanced by using proper management of vegetation and area expansion of the present CW.

Arsenic health risk assessment in drinking water and source apportionment using multivariate statistical techniques in Kohistan region, northern Pakistan.

The present study was conducted in Kohistan region, where mafic and ultramafic rocks (Kohistan island arc and Indus suture zone) and metasedimentary rocks (Indian plate) are exposed. Water samples were collected from the springs, streams and Indus river and analyzed for physical parameters, anions, cations and arsenic (As(3+), As(5+) and arsenic total). The water quality in Kohistan region was evaluated by comparing the physio-chemical parameters with permissible limits set by Pakistan environmental protection agency and world health organization. Most of the studied parameters were found within their respective permissible limits. However in some samples, the iron and arsenic concentrations exceeded their permissible limits. For health risk assessment of arsenic, the average daily dose, hazards quotient (HQ) and cancer risk were calculated by using statistical formulas. The values of HQ were found >1 in the samples collected from Jabba, Dubair, while HQ values were <1 in rest of the samples. This level of contamination should have low chronic risk and medium cancer risk when compared with US EPA guidelines. Furthermore, the inter-dependence of physio-chemical parameters and pollution load was also calculated by using multivariate statistical techniques like one-way ANOVA, correlation analysis, regression analysis, cluster analysis and principle component analysis.

Relationship between the concentration of copper and iron in the aqueous humour and intraocular pressure in rabbits treated with topical steroids

Purpose: To evaluate the concentration of copper and iron in the aqueous humour of steroid‐treated eyes, particularly to study the concentration of these metals in relation to steroid‐induced increases in intraocular pressure (IOP).

Petrogenesis of granites from the Utla area of Gadoon, north-west Pakistan: Implications from petrography and geochemistry

The granitic rocks around the Utla area (Gadoon), north western, Pakistan are studied in terms of their petrographic features and geochemical characteristics. Although predominantly mega-porphyritic, some of the Utla granites are massive and display fine-grained equi-granular texture. Some of the mega-porphyritic varieties exhibit foliation and seem to be restricted to shear zones. In addition to being distributed largely as phenocrysts, all the essential minerals (plagioclase, perthitic alkali feldspar and quartz) also constitute the groundmass. The studied samples also contain minor to accessory amounts of tourmaline, muscovite and biotite and accessory to trace amounts of apatite, andalusite, garnet, zircon, monazite, epidote and sphene. A detailed geochemical investigation reveals a calc-alkaline and peraluminous character of the Utla granites. The peraluminous character and total lack of hornblende designate their S-type character while a volcanic arc or syn-collisional tectonic setting for their emplacement is indicated by discrimination diagrams. Further examination shows that the melt parental to the Utla granite was derived from a plagioclase-poor, clay-rich rock, i.e., pelite. The petrogenetically significant petrographic and geochemical features of the Utla granite show greater similarity with the Mansehra than the Ambela granites. These include (i) the predominantly megaporphyritic texture, (ii) the presence of andalusite and tourmaline, (iii) the calc-alkaline geochemical signature and (iv) an indication of similar melt source rock character.

ENVIRONMENTAL GEOCHEMISTRY OF ACID MINE DRAINAGE WATER AT INDUS COAL MINE AT LAKHRA, SINDH-PAKISTAN

The annual coal production of Pakistan is about 3,637,825 tonnes which is about 6% of the countrys energy resources; out of this 1,241,965 tonnes of coal was produced/mined from the Lakhra coalfield, District Dadu, Sindh which after the Thar coal field is the second largest coalfield of Pakistan. At this coal field more than 58 mining companies are engaged in exploring the hidden wealth of the country. The problem of Acid Mine Drainage, is caused by the passage or seepage of water, through mines where iron disulphides, usually pyrites, are exposed to the oxidizing action of water, air and bacteria, is the main problem faced by the mining companies. The geochemical analysis of acid mine drainage water collected from Indus coal mine No. 6 shows that beside its higher pH, Total Dissolved Solids and Sulphates, it also posses higher amount of heavy metals like Cd, Cu, Pb, Co, Ni, and Fe. This acid mine drainage water not only damages the mine structures but is also harmful to soil and ecology.