Reproductive toxicity of lead,cadmium, and phthalate exposure in men

Environmental toxicants viz lead or cadmium and phthalate esters (di(2-ethylhexyl) phthalate [DEHP], dibutyl phthalate [DBP], and diethyl phthalate [DEP]) widely found in different environmental strata are linked to deteriorating male reproductive health. The objective was to assess the relationships between the seminal lead, cadmium, and phthalate (DEHP, DBP, DEP) concentrations at environmental level and serum hormone levels and semen quality in non-occupationally exposed men and specify the effect of individual and combined exposure of toxicants on semen quality. A study of 60 male partners of couples attending the Andrology Laboratory of the Reproductive Biology Department, All India Institute of Medical Sciences (AIIMS), New Delhi, India for semen analysis to assess their inability to achieve a pregnancy was selected for the study. The results of univariate and stepwise multiple regression analysis in the unadjusted model showed a significant correlation between lead or cadmium and phthalates DEHP/DBP/DEP and sperm motility, sperm concentration, and DNA damage. After adjusting for potential confounders, an association with lead or DEHP was only observed. The present data shows that lead (Pb) or cadmium (Cd) or phthalates might independently contribute to decline in semen quality and induce DNA damage. Phthalates might influence reproductive hormone testosterone. These findings are significant in light of the fact that men are exposed to a volley of chemicals; however, due to the small sample size, our finding needs to be confirmed in a larger population.     

Formulation of a landfill pollution potential index to compare pollution potential of uncontrolled landfills

Generally speaking, landfilling is one of the prominent methods of waste disposal around the globe, but some under-developed and developing countries still continue to practice uncontrolled open dumping of waste. These uncontrolled landfills pose a relatively high threat to the various elements of the environment in comparison with the conventional engineered landfills that are used in many developed countries. However, some closed, un-engineered landfills do exist in developing countries. This paper presents a novel approach to compare the pollution potential of uncontrolled landfills using an index. The landfill pollution potential index (LPPI) has been developed using the Delphi technique and is an aggregation of six pollution indices that have already been developed for the quantification of different environmental elements. The LPPI is an increasing scale index, in which a higher index value indicates a higher pollution threat. The LPPI of a landfill in Delhi was calculated and the high LPPI value indicates that the respective landfill poses a significant threat to the environment. The LPPI can be used as an aid to diagnose a landfill's pollution potential relative to other landfills and therefore also to rank remediation investments.     

Toxicity and uptake of mercurials in a cyanobacterium

Nostoc calcicola cells exposed to mercuric chloride (0.05–0.25 M), methyl mercuric chloride (0.05–0.15 M) and the fungicide ceresan (phenyl mercuric acetate; 0.05–0.20 M) showed sensitivity in the sequence: methyl mercury3) over phenyl mercuric acetate (0.51×10³); inorganic mercury occupied the intermediate position with a bioconcentration factor of 1.32×10³. The data infer that larger molecules of organomercurials may not be taken up by cells at the rate and extent comparable to the smaller species.     

Nitrogen and sulphur mustard induced histopathological observations in mouse visceral organs

Nitrogen mustards (HN) and sulphur mustard (SM) are potent alkylating blister inducing chemical warfare agents. Single 1.0 LD50 dose produced a progressive fall in body weight from second day onwards in all groups of mustard agents exposed animals. Histological examination of spleen, liver skin and kidney revealed significant histopathological lesions in nitrogen mustards and sulphur mustard. These lesions include granulovascular degeneration with perinuclear clumping of the cytoplasm of hepatocytes and renal parenchymal cells. Renal lesions were characterized by congestion and hemorrhage. The maximum toxic manifestation were noted in spleen and skin of HN-3 exposed mice while sulphur mustard reported maximum toxicity in liver and kidneys. The study suggests both nitrogen mustards and sulphur mustard to be extremely toxic by percutaneous route based on histopathological observation and can contributed to earlier reported free radical generation by these toxicants.     

Phosphorus sorption characteristics of estuarine sediments under different redox conditions

Phosphorus (P) plays a major role in eutrophication of aquatic systems. Estuarine sediments could function as sources or sinks for P to the overlying water column depending upon their physico-chemical characteristics. Understanding of P sorption phenomena in estuarine sediments is important in regulating the P availability in estuaries. Phosphorus sorption characteristics of sediments from the Indian River Lagoon, Florida, USA, were determined to examine the role of selected physico-chemical properties of the sediments on soluble reactive P status in estuary water. Mean equilibrium P concentrations (EPCo) of 0.75 mg L(-1) and mean P sorption maxima (Smax) of 32.2 mg kg(-1) were obtained under anaerobic conditions, compared with EPCo of 0.05 mg L(-1) and Smax of 132.7 mg kg(-1) under aerobic conditions. The higher EPCo values under anaerobic conditions and the greater Smax values under aerobic conditions were associated with amorphous and poorly crystalline iron. These results suggest that sediments enriched with amorphous and poorly crystalline forms of iron act as an excellent reservoir for P by adsorbing excessive P in aerobic sediment zones and releasing it upon burial under anaerobic conditions. This study also indicates that P compounds in sediments independently maintain equilibrium with P in solutions. Thus, heterogeneous systems like soil and sediment simply behave as a mixture of homogeneous surfaces as far as their P sorption characteristics are concerned, and hence can be successfully described by the Langmuir and Freundlich models.     

Chemical and biological extraction of metals present in E waste: A hybrid technology

Management of metal pollution associated with E-waste is widespread across the globe. Currently used techniques for the extraction of metals from E-waste by using either chemical or biological leaching have their own limitations. Chemical leaching is much rapid and efficient but has its own environmental consequences, even the future prospects of associated nanoremediation are also uncertain. Biological leaching on the other hand is comparatively a cost effective technique but at the same moment it is time consuming and the complete recovery of the metal, alone by biological leaching is not possible in most of the cases. The current review addresses the individual issues related to chemical and biological extraction techniques and proposes a hybrid-methodology which incorporates both, along with safer chemicals and compatible microbes for better and efficient extraction of metals from the E-waste.     

Tourism and wetland conservation: application of travel cost and willingness to pay an entry fee at Ghodaghodi Lake Complex,Nepal

This study investigated the need and applicability of wetland tourism for resource conservation, using the case of Ghodaghodi Lake Complex, a Ramsar Site in western Nepal. The travel cost method (TCM) was used to determine the recreation potential of the lake complex, while the contingent valuation method (CVM) was used to calculate willingness of visitors to pay an entry fee as a payment vehicle for conservation. The per capita travel cost was found to be NPR 540 (US $7.71), while the mean willingness to pay an entry fee was NPR 34 (US $0.48) per visitor per entry. In addition, factors affecting wetland visitation rates and maximum willingness to pay were identified. Policy implications include the establishment of an entry fee system to offset conservation budgetary constraints, government investment in social benefits equating to at least per capita travel cost identified, and public‐private partnerships, with community participation in tourism promotion and wetland conservation.