Home > Application of Biochar in Reducing the Levels of Pesticide Residues in Contaminated Soils and Food Crops: A Strategy to Minimize the Health Risk
Application of Biochar in Reducing the Levels of Pesticide Residues in Contaminated Soils and Food Crops: A Strategy to Minimize the Health Risk
Organochloride pesticides (OCPs) also known as ―endocrine disrupting‖ chemicals are one of the persistent group of contaminants in soil that has gained worldwide concerns over the past few decades. They can transferred into the vegetables grown on the contaminated soils and eventually entered the food chain. The associated risk to human health makes the remediation of pesticide-contaminated soil a crucial undertaking. This research work is divided into different parts and several experiments were conducted to achieve the proposed objectives. The first study was carried out to evaluate the concentrations of OCPs in soils and vegetables grown in selected sites of Khyber Pakhtunkhwa (KP), Pakistan. The soil and selected vegetable species including Spinacia oleracea, Raphanus sativus, Brassica rapa, Lactuca sativa, Allium cepa and Allium sativum were collected from six districts (Peshawar, Charsadda, Nowshera, Mardan, Swabi and Swat), and were analysed for selected OCPs. Results showed that the concentrations of the selected OCPs exceeded their respective maximum residue limits (MRLs) in most of the soil samples and showed great variation from site to site. In case of the studied vegetables, the most contaminated observed was Lactuca sativa (28.9 μg kg-1), followed by Raphanus sativus (26.6 μg kg-1), Spinacia oleracea (25.8 μg kg-1), Allium cepa (16.3 μg kg-1), Brassica rapa (15.6 μg kg-1), and Allium sativum (14.7 μg kg-1). Analysis of health risk revealed that incremental lifetime cancer risks (ILCR) associated with dietary exposure of Σ30OCP through vegetables consumption by adults and children were below the acceptable risk level (10-6), indicating no cancer risk to the consumers. Moreover, exposure to the endocrine disruptor and probable carcinogen heptachlor epoxide (in children only) contributes toward non-cancer risk (HQ>1) from ingestion of selected vegetables. The presence of the banned OCPs in soils and vegetables in xvi the study area indicates that these legacy chemicals are still being used illegally for agricultural purposes which may be a cause for concern. Similarly, the second study was focused on the remediation of OCP-contaminated soils, as most of the OCPs are known to be possible/suspected endocrine disruptors and carcinogenic in nature and may severely affect humans or other living biota. Therefore, a 65-d incubation experiment was conducted to investigate the efficacy of biochars on the accessibility of OCPs, and also to evaluate their influence on soil microbial community. Results indicated that despite greater persistence of OCPs in soil, the application of selected biochars significantly (p<0.01) reduced the accessibility of åOCPs in contaminated soil as compared to the control soil during 65-days incubation period. Moreover, the findings from total phospholipid acid (PLFA) and Illumina next-generation sequencing revealed that the incorporation of biochar have altered the soil microbial community structure over time. Higher abundances of Proteobacteria, Firmicutes, Gemmatimonadetes, and Actinobacteria, were found in the biochar amendments. This recommends that biochar amendment (3%) could be advantageous for sustaining soil microbial communities and may thus likely influence the eco-toxicological processes and potential accumulation of OCPs. The third study was conducted to evaluate the effects of biochar (BC), biochar-based organic fertilizer (OF) and their combination (BCOF) on the bioaccessibility and accumulation of endocrine disruptive pesticides (EDPs) into leafy vegetables (Lactuca sativa and Spinacia oleracea) grown in a contaminated soil. The results revealed that application of BCOF and OF significantly (p<0.05) decreased bioaccessible concentrations of åEDPs in leafy vegetables by 23 and 44%, respectively, BC was particularly effective and decreased åEDPs bio-accessible concentrations by 60%, as compared to control. Biomass production, however, xvii increased the most for the BCOF amendments, (with a 70% increase in crop production compared to the control soil). Moreover, the incremental lifetime cancer risk (ILCR) values for selected EDPs were significantly (p<0.01) reduced in the amended soil as compared to control. These findings suggest that OF, BCOF and BC could be useful soil amendments to minimize the EDPs bioaccessibility in a degraded soil and their subsequent exposure to humans through vegetable consumption. Likewise, to investigate the effects of different biochars on the bioaccessible fractions of OCPs in a contaminated soil and their subsequent bioaccumulation into vegetable crops a fourth study was conducted. Four different biochars, derived from sewage sludge, soybean straw, rice straw and peanut shells were applied to a pesticide-contaminated soil at 2%, and the resulting impacts were measured. The results indicated that following biochar additions, the bioaccessible fractions of OCPs in soil and their accumulation in vegetable crops significantly (p<0.01) reduced, as compared to control. Risk assessment showed that biochar amendments markedly (p<0.01) decreased the hazard quotient (HQ) indices and the incremental lifetime cancer (ILCR) values for OCPs associated with the consumption of vegetable crops. From the results of the present studies it is concluded that the application of biochar could play a promising role in enhancing microbial abundance, reducing accessibility, restricting bioaccumulation of organochlorine pesticides in vegetables and decreasing their associated human health risk.
The Immensely Merciful to all, The Infinitely Compassionate to everyone.
60:01 a. O The Faithful! b. Do not take MY enemies and your enemies as friends, c. expressing affection for them while they disbelieve in the Truth - The Qur’an - which has come to you; d. such has been their enmity that they drive out the Messenger and yourselves from your homes in Makkah just because you believe in Allah - The One and Only God, your Rabb - The Lord – e. do not make them friends if you truly emigrated in order to strive in MY Cause and seek MY Pleasure, f. and at the same time, you show them affection in secret accords - g. whereas I Know very well whatever you hide and whatever you disclose. h. And whoever among you does so has indeed strayed far away from the right way.
60:02 a. While on the other hand, should they encounter you in a battle-like situation and gain upper hand over you, they will treat you like bitter enemies, b. and stretch out their hands as well as their tongues against you with malice, c. and they would love to see you returning to disbelief as they are.
60:03 a. Remember that your relatives and your children would not be of any benefit to you during the Time of the Resurrection. b. HE will separate you out. c. And Allah is always Watching over whatever you do.
60:04 a. There has, indeed, been an excellent example set for you to emulate by Abraham and those with him like Lot, when they...
This study aims to find the implementation of hypnoteaching method in fiqh (Islamic law) learning in Madrasah Tsanawiyah NU Sunan Kalijaga, Adiwerna Tegal, Central Java. This research is a qualitative research, which is a case study. Data sources of this research are interviews and varius literature on hypnoteaching. There are two big conclusions in this research. First, the hypnoteaching method is a learning method that involves cognitive, affective and psychomotor aspects of students through positive suggestions. Second, the application of hypnoteaching fiqh learning in the field works effectively related to the synergy between the principles of hypnoteaching and the existing implementation plan of learning. However, there are still inhibiting factors, namely the minimum number of teachers who have competence in the application of hypnoteaching.
The aim of present research is to define and analyze some new families of holomorphic mappings related to the conic domain. Different techniques and tools are employed to investigate these families including differential subordination, Bernardi integral operator, Carlson-Shaffer linear operator, hypergeometric mapping, convolution operator, real and the complex orders. These families are extensively explored by studying their coefficient bounds, arc length problems, covering results, integral representations, inclusion results, radius of convexity problems, necessary conditions, growth rate of coefficients, distortion results, subordination results, convolution preserving properties and Fekete-Szegö inequality. Numerous well-known results appear as special cases for the different choices of parameter from our main results. Our investigation also contains a sound relationship between the results presented here with the results which are already available in the literature.