Pesticide residues in fruits and vegetables from Pakistan: a review of the occurrence and associated human health risks

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.     

Report: Healthcare waste characterization in Chittagong Medical College Hospital, Bangladesh

Healthcare waste management (HCWM) options are inconsistent in Bangladesh. One of the first critical steps in the process of developing a reliable waste management plan requires a comprehensive understanding of the quantities and characteristics of the waste that needs to be managed. This study took into consideration both the quantity and quality of the generated waste to determine the generation rates and physical properties of healthcare waste (HCW) in Chittagong Medical College Hospital (CMCH) and also to estimate the amount of infectious and non-infectious waste generated in different wards. CMCH, the second largest hospital in Bangladesh, comprises 34 wards, 12 of which were selected randomly. Waste materials were collected from these wards and then segregated and weighed. Waste generation per day was found to be 73.22 kg/ward, 1.28 kg/bed and 0.57 kg/patient. A total of 2490 kg of HCW was produced each day in CMCH (37% being infectious and the rest being non-infectious waste). Infectious waste was 27.07 kg per ward, 0.47 kg per bed and 0.21 kg per patient and the non-infectious waste was 46.15 kg per ward, 0.81 kg per bed and 0.36 kg per patient per day. HCW comprised eight categories of waste materials with vegetable/food waste being the largest component (50.21%) and varied significantly (P < 0.05) among the 12 different wards studied. The greatest amount of HCW was recorded (154 kg) in Orthopaedics followed by 96.66 kg in the Medicine Unit-3 and the smallest amount was recorded in Casualty (8.79 kg). The amount of HCW was positively correlated with the number of occupied beds (rxy = 0.79, P < 0.01). There is no structured form of medical waste treatment in CMCH and most waste materials are dumped in open areas for natural degradation or re-sold by scavengers. It is essential to develop a national policy and implement a comprehensive action plan for HCWM that will provide environmentally sound technological measures to improve HCWM in Bangladesh.     

Spatio-temporal variations in water quality of Nullah Aik-tributary of the river Chenab, Pakistan

This study reports the spatio-temporal changes in water quality of Nullah Aik, tributary of the Chenab River, Pakistan. Stream water samples were collected at seven sampling sites on seasonal basis from September 2004 to April 2006 and were analyzed for 24 water quality parameters. Most significant parameters which contributed in spatio-temporal variations were assessed by statistical techniques such as Hierarchical Agglomerative Cluster Analysis (HACA), Factor Analysis/Principal Components Analysis (FA/PCA), and Discriminant Function Analysis (DFA). HACA identified three different classes of sites: Relatively Unimpaired, Impaired and Less Impaired Regions on the basis of similarity among different physicochemical characteristics and pollutant level between the sampling sites. DFA produced the best results for identification of main variables for temporal and spatial analysis and separated eight parameters (DO, hardness, sulphides, K, Fe, Pb, Cr and Zn) that accounted 89.7% of total variations of spatial analysis. Temporal analysis using DFA separated six parameters (E.C., TDS, salinity, hardness, chlorides and Pb) that showed more than 84.6% of total temporal variation. FA/PCA identified six significant factors (sources) which were responsible for major variations in water quality dataset of Nullah Aik. The results signify that parameters identified by statistical analyses were responsible for water quality change and suggest the possibility of industrial, municipal and agricultural runoff, parent rock material contamination. The results suggest dire need for proper management measures to restore the water quality of this tributary for a healthy and promising aquatic ecosystem and also highlights its importance for objective ecological policy and decision making process.     

A comprehensive review of hydrophobic silica and composite aerogels: synthesis,properties and recent progress towards environmental remediation and biomedical applications

Environmental Science and Pollution Research - The hydrophobicity of silica and composite aerogels has enabled them to acquire applications in a variety of fields. With remarkable structural,...     

Synthesis and characterization of drinking water treatment plant sludge-incorporated Portland cement

Kinetic analysis of thermally activated phase transformations in drinking water treatment plant (DWTP) sludge suggests its applicability in the materials of construction. The suggested prediction has already been verified on the sludge-based bricks. The present study deals with incorporating the same sludge in the raw meal for the synthesis of Portland cement clinkers. For this purpose, two raw meals are prepared with varying sludge loadings. The sludge effect on reactivity of the crude mixture is evaluated on the basis of the free lime content sintered at various elevated temperatures. The results of chemical and mineralogical and scanning electron microscopic analyses reveal fine mineralogical contents of Portland clinkers calcined at 1450 and 1500 °C. Moreover, the cements prepared from these clinkers by the introduction of certain proportions of gypsum, depict significant durability. The obtained results elucidate that the studied DWTP sludge-incorporated Portland cement shows considerable potential to be commercialized.     

Movement towards a low carbon emitted environment: a test of some factors in Malaysia

There exists a high global concern in different nations on environmental sustainability especially at the focal stage of increased economic growth and development process due to high level of environmental degradation and pollution. The major aim of this study was to empirically examine how to minimise carbon emissions (CO₂) in Malaysia which are mainly caused by energy production, fossil fuel consumption, population density and economic growth. The study adopted the method of autoregressive distributed lag bound testing approach to analyse the data for the period 1971–2011. The study found that economic growth in Malaysia has a direct relationship with CO₂ emissions in both the short run and the long run. Similarly, there is a positive relationship between fossil fuel consumption and CO₂ emissions over the same period. Population density was found to have positive impacts on CO₂ emissions. Contrarily, the relationship between the activities of energy production and pollution is negative in the long run. The study recommends that a targeted GDP growth rate should be set with the consideration to avoid more environmental pollution. In addition, the positive impact of fossil fuel consumption on the environmental pollution implies that there is a need to make and implement policies that will encourage the use of public transportation system more than private transportations. That is, the unnecessary use of private vehicles should be discouraged in order to reduce the extent of fossil fuel consumption.     

Analyzing the role of information and telecommunication technology in human development: panel data analysis

Environmental Science and Pollution Research - Economic growth in modern-day world get attention primarily through innovation and higher productivity, which places technology and knowledge at the...     

Nanoparticles functionalized ceramic membranes: fabrication,surface modification,and performance

Environmental Science and Pollution Research - Membrane technologies are used intensively for desalination and wastewater treatment. Water filtration using ceramic membranes exhibited high...     

Preparation and characterization of polycaprolactone nanocapsules containing pretilachlor as a herbicide nanocarrier

Polycaprolactone nanocapsules (PCL) containing pretilachlor were prepared, and Fourier transform infrared spectroscopy, atomic force microscopy, and transmission electron microscopy were used for their structural and morphological investigations. The results revealed that the nanocapsules had irregular shape and their particles size was in the range of 70–200 nm. The encapsulation efficiency of pretilachlor was measured as 99.5 ± 1.3% using high-performance liquid chromatography analysis. The physicochemical stability studies over 60 days showed that the nanocapsules were stable in the suspension without any aggregation. The herbicide activity was examined in a pre-emergence manner using barnyard grass as a target plant and rice as a non-target plant. The nanoformulation had no negative effect on rice plant. However, its effect on barnyard grass was significant. The cytotoxicity analysis indicated that the nanocapsulated herbicide is less toxic rather than the commercial formulation. Therefore, encapsulation of pretilachlor in PCL nanocapsules can be used effectively to construct environmentally friendly PCL-herbicide systems in agriculture.

     

Nano-inspired systems in food technology and packaging

Creation of food-based nanomaterials for food processing and packaging applications is actually gaining in importance. Indeed, the design of a suitable food carrier system controls the encapsulation efficiency, the product stability and release of bioactives such as micronutrients, antimicrobial compounds and antioxidants. The smaller size of nanomaterials provides higher thermodynamic and kinetic stability. Whereas the higher surface area enhances compound solubility. Nanoemulsions both encapsulate bioactive compounds effectively and address the food safety concerns of the fresh produce associated with foodborne pathogens. Nanoliposomes encapsulate bioactive whey peptides and fat-soluble vitamins with improved functionalities. Encapsulated bioactive molecules are released by diffusion into the surrounding environment after degradation of the surrounding polymeric matrix.