Bulletin of Environmental Studies

63-68

Authors: Muhammad Zia ur Rehman, Inaam Ullah*, Sajid Abdullah

This study was performed to determine acute toxicity of a mixture of five water-borne metals (iron, zinc, lead, nickel and manganese) to fresh water fish species Cirrhina mrigala L. We performed acute toxicity assays to determined LC50 (concentration at which 50% fish die) and LC95 (concentration at which 95% fish die) of the metals mixture after 96 hours of exposure to one-month old fish specimens. All the assays were performed in glass aquaria of 100 liters volume. We found significant difference between LC50 (26.84 mg L-1) and LC95 (70.42 mg L-1) of metals mixture for C. mrigala. The amount of total sodium, potassium and calcium increased with increasing concentration of the metals mixture, as did total ammonia in the test medium however, concentration of magnesium decreased significantly. We also observed increased use of oxygen by the fish under stress of heavy metals mixture, and in turn accelerated carbon dioxide release into the water that increases water pollution. We conclude that the tested metals mixture is highly toxic to C. mrigala. Further work is recommended to unearth molecular basis of, and synergistic effects of the metals toxicity to fish fauna.

75-81

Authors: Rabia Arshad*, Almas Hamid, Asrar Ahmad Kazi, Nikhat Khan

The heavy metal contamination from an occupational origin is of major concern due to its accumulation in living organisms leading to long term toxic effects. The present study estimated the quantities of manganese and chromium in blood, urine, and hair of welders and non-welders (n = 25) (ages ranged from 16 to 50 years) in Lahore, Pakistan. The results indicated that both manganese and chromium were higher in all the samples compared to the international norms by world health organization (WHO), (i.e., 20-80 ppb in blood, 1-8 ppb in urine, and 300 ppb in hair for manganese while 20-50 ppb in blood, 0.24-1.8 ppb in urine and 100-1000 ppb in hair respectively). Though one of the subject was of 50 years and had 32 years of experience, his manganese and chromium amounts were less because he was the owner of the shop and was currently less exposed to the fumes. The statistical data was in accordance with the finding of the study; whereas control group showed manganese and chromium levels within limits.

88-89

Authors: Muhammad Arslan*, Inaam Ullah

Meta-analysis is a modern statistical approach that combines the results from multiple studies to enhance the power of data, improves the quality of estimates, and the magnitude of the effect of a treatment. In bio/phyto-remediation studies, some authors adopt general ways to present research outcomes such as percentages, means, and graphs. This type of data has multiple limits, non-availability of comparative statistical significance and publication bias are the most imperative. In addition, such data creates big hindrances to perform metaanalysis in a cluster of other studies. Consequently, such datasets restrict the statistical comparison between similar studies, and quantitative assessment of variables. Hence, newcomers in the field of bioremediation find it difficult to design effective test protocols, and at the end, have to content with unconvincing results. Therefore, we suggest presentation of actual data along with statistical analyses of observations, and comparison with the control for robust translation of results. Otherwise, the authors must be directed to publish original datasets as supporting material or appendices with the manuscript.