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211.
The present research focuses on estimating forest area change with respect to the ongoing forest land conversion. The study tests the hypothesis that forest land is being converted to the selected land use categories with high growth tendency and controlling deforestation rate to its half of the present level would significantly improve the land cover under forest. The rate of forest land conversion to other land use categories is analyzed and then compared with the total area expanded under three land use classes. We used Systems dynamic modeling approach to estimate forest area by simulating forest land conversion in Pakistan, projecting to 2030. The results show that rangeland, built-up area and cultivated land have increased over time; growth rate of built-up area (9%) is highest followed by rangeland area (1.7%) and cultivated area (0.3%), respectively; rangeland is the dominant category in terms of area expanded (0.74 m. ha). Sensitivity analysis showed that reducing deforestation rate to half of the past level of 1% could not significantly improve forest area; therefore, it is suggested that controlling deforestation alone is not an effective strategy unless drastic measures, e.g., demarcation of forest boundaries, land use control policy and afforestation campaign would be started in the country.  相似文献   
212.

Pakistan is an agricultural country and due to the shortage of clean water, most of the irrigated area (32,500 ha) of Pakistan was supplied with wastewater (0.876?×?109 m3/year). Concentrations of heavy metals in radish (Raphanus sativus) and turnip (Brassica rapa) taken from vegetable fields in Sargodha, Pakistan, were measured. Untreated wastewater was used persistently for a long time to irrigate these vegetable fields. A control site was selected that had a history of fresh groundwater irrigation. Mean metal concentrations were found for irrigation water, soil, and vegetables. In irrigation water, concentrations of Mo and Pb at three sites and Se at sites II and III were higher than the recommended limits. In vegetables, concentrations of Mo and Pb were above the maximum permissible limits. High bioconcentration factor was observed for Zn (12.61 in R. sativus and 11.72 in B. rapa) at site I and high pollution load index was found for Pb (3.89 in R. sativus and 3.87 in B. rapa) at site II. The differences in metal concentrations found in samples depended upon different soil nature and assimilation capacities of vegetables at different sites which in turn depended upon different environmental cues. The entrance of metal and metalloids to human body may happen through different pathways; however, the food chain is the chief route through which metals are transferred from vegetables to individuals. Health risk index observed for metals, (Mo, As, Ni, Cu, and Pb) higher than 1 indicated high risk through consumption of these vegetables at three sites.

  相似文献   
213.
Environmental and Ecological Statistics - The paper proposes a new perspective in the environmental and resource economics literature by examining innovation (measured by R&D expenditures),...  相似文献   
214.

With the rapid industrialization, especially offshore oil exploitation, frequent leakage incidents of oils/organic solvents have adversely affected ecological systems and environmental resources. Therefore, great interest has been shown in developing new materials to eliminate these organic pollutants, which have become worldwide problems. In this study, a cost-effective, environmentally friendly porous aerogel with three-dimensional (3D) structure was prepared from grapefruit peel by a facile hydrothermal method as the adsorbent of oils/organic solvents. The as-prepared modified grapefruit peel aerogel (M-GPA) showed mesoporous structure with high specific surface area of 36.42 m2/g and large pore volume of 0.0371 cm3/g. The excellent hydrophobicity of M-GPA with a water contact angle of 141.2° indicated a strong potential for adsorption of oils and organic solvents. The high adsorption capacity of M-GPA for a series of oils and organic solvents was 8 to 52 times as much as its own weight. Moreover, the M-GPA was easily regenerated and a high adsorption capacity recovery above 97% was maintained after five adsorption–regeneration cycles. Therefore, the M-GPA is a promising recyclable adsorbent for the removal of oils/organic solvents from polluted water.

  相似文献   
215.
Jaafar  Hadi  Ahmad  Farah  Holtmeier  Lauren  King-Okumu  Caroline 《Ambio》2020,49(6):1179-1193
Ambio - The Syrian crisis caused a massive influx of displaced people into neighboring countries, with Lebanon hosting the highest per capita number of refugees (3:10). Water remains the most...  相似文献   
216.
Environmental Science and Pollution Research - This study was designed to assess the gradual increase in the use of insecticides on vegetables and to familiarize the consumers regarding the...  相似文献   
217.
Environmental Science and Pollution Research - Climate change is occurring and is influencing biological systems through augmented temperatures, more inconstant precipitation, and rising CO2 in the...  相似文献   
218.
The main objective of the review is to document, assess and analyze the results of the previously reported data on levels of different pesticides in selected fruits and vegetables from Pakistan. The findings of the previous studies clearly indicated that more than 50 % of the samples were contaminated with organophosphate, pyrethroids and organochlorine pesticides. Many studies reported that among fresh fruits and vegetables tomato, apple, melon, mango, grapes, and plum crossed the FAO/WHO permissible limits for these contaminants residual levels. The comparison of other regions showed that observed levels were found above maximum residue limits (MRLs) in 50 % of the samples but were in agreement with the studies from neighboring countries like China and Bangladesh. Higher hazard risk index (HRI) values were calculated for dieldrin, methamidophos, o,p′-DDT, diazinon and p,p′-DDT in apple, mango, banana, melon, potato and onion. The review also highlights that data on pesticide residues in foodstuff is scarce which should be overcome by further extending studies from different areas of Pakistan. In order to ascertain the provision of food suitable for human consumption, it is imperative to monitor pesticides in food commodities by the country’s authorities and enforce guidelines based on permissible limits.  相似文献   
219.
The study was conducted to assess the effects of in utero di-butyl phthalate (DBP) and butyl benzyl phthalate (BBP) exposure during late gestation on offspring’s development and reproductive system of male rats. Pregnant rats were treated orally with DBP (2, 10, 50 mg/kg), BBP (4, 20, 100 mg/kg), and diethylstilbestrol (DES) 6 μg/kg (positive control) from GD14 to parturition. A significant reduction in dams’ body weight on GD21 in DBP-, BBP-, and DES-treated groups was observed. The gestation length was considerably elevated in the treated groups. Decline in male pups’ body weight was significant at PND75 in DBP- (50 mg/kg), BBP- (20,100 mg/kg), and DES-treated groups. The weight of most of the reproductive organs and sperm quality parameters was impaired significantly in DBP- (50 mg/kg) and BBP- (100 mg/kg) treated groups. Further, a non-significant decline in testicular spermatid count and daily sperm production was also monitored in treated groups. A significant reduction in serum testosterone level in BBP (100 mg/kg), whereas the testicular activity of 17β-HSD was declined non-significantly in the treated groups with respect to control. The data suggests that DBP and BBP exposure during late gestation period might have adverse effects on offspring’s development, spermatogenesis, and steroidogenesis in adult rats.  相似文献   
220.
This paper examines the implications of oil palm estate development in Indonesia’s frontier province of Papua. Government planners believe that oil palm investment will develop the local economy, create jobs and reduce poverty. Using the input–output approach, we find that, in aggregate terms, oil palm investments boost the economic output in the province, generate jobs and increase worker salaries. However, the oil palm subsector operates in isolation and has limited economic multipliers. The number of jobs is potentially large, but those best positioned to benefit from them are mostly skilled migrants, not local poor. The government should reduce the size of plantation investments and plan their implementation as part of a broader development package to allow greater economic integration and skill acquisition by local communities. The priority areas for plantation development should be degraded, non-forest land.  相似文献   
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