Studies on peri urban farming in Zambia have not adequately tackled the issues pertaining to heavy metal contaminated wastewater irrigation farming. The study investigated heavy metal contamination of water, soils and...Studies on peri urban farming in Zambia have not adequately tackled the issues pertaining to heavy metal contaminated wastewater irrigation farming. The study investigated heavy metal contamination of water, soils and crops at two peri urban areas in Zambia. Two study sites were New Farm Extension in Mufulira Town in the Copperbelt Province and Chilumba Gardens in Kafue Town in Lusaka Province. The heavy metals investigated were lead, copper, cobalt, nickel and chromium. These heavy metals were found to be higher than acceptable limits in wastewater used to irrigate crops and there are potential human health risks associated with consumption of heavy metal contaminated food crops which have implications on the livelihoods of people. Samples of water, soil and crops were collected and analysed for lead (Pb), copper (Cu), chromium (Cr), cobalt (Co) and nickel (Ni) using the Atomic Absorption Spectrometer (AAS). The data on heavy metals was analysed using mean, standard error and T-test. The results indicated that the levels of heavy metals in wastewater, soil and food crops were above acceptable limits at two study sites. It can be concluded that there was heavy metal contamination of wastewater, soil and food crops at the two peri-urban areas in Zambia. The study highlighted the actual levels of heavy metal contaminant uptake in food crops consumed by the peri urban population. The information from this study can be used by the relevant authorities to develop appropriate measures for monitoring and control of heavy metal contamination in wastewater irrigation farming systems in peri urban areas inZambia.展开更多
Mycotoxins are secondary metabolites produced by several fungal species and molds.Under favorable conditions like high temperature and moisture,they contaminate a large number of food commodities and regional crops du...Mycotoxins are secondary metabolites produced by several fungal species and molds.Under favorable conditions like high temperature and moisture,they contaminate a large number of food commodities and regional crops during pre and post-harvesting.Aflatoxin is the main mycotoxin that harm animal and human health due to its carcinogenic nature.Aflatoxins are mainly released by Aspergillus flavus and Aspergillus parasiticus.AFB1 constitutes the most harmful type of aflatoxins and is a potent hepato-carcinogenic,mutagenic,teratogenic and it suppresses the immune system.To maintain food safety and to prevent aflatoxin contamination in food crops,combined approaches of using resistant varieties along with recommended farming practices should be followed.This review concentrates on various aspects of mycotoxin contamination in crops and recent methods to prevent or minimize the contamination.展开更多
There are two pathways for nitrate to enter into human body: drinking water and food. Therefore, nitrate contamination of drinking water and agricultural crops is of particular interest to governments and the general ...There are two pathways for nitrate to enter into human body: drinking water and food. Therefore, nitrate contamination of drinking water and agricultural crops is of particular interest to governments and the general public owing to the possible implications for health. This work investigated nitrate contents in various crops and in different parts of each crop and in drinking water as well in the Zhangye Basin, Northwest China. It provided evidence of severe nitrate contamination of drinking water, especially, in vegetable-growing villages. As to the nitrate contamination of crops, the present study revealed that all sampled crops adjust their nitrate distributions in a way that the edible parts contain much less nitrate than non-edible parts except lettuce. The nitrate content in the edible root of lettuce reached up to 5900 mg/kg exceeding the limit set by the European Commission.展开更多
Chlordecone, one of the most persistent organochlorine pesticides, was applied between 1972 and 1993 in banana fields in the French West Indies, which results in long-term pollution of soils and contamination of water...Chlordecone, one of the most persistent organochlorine pesticides, was applied between 1972 and 1993 in banana fields in the French West Indies, which results in long-term pollution of soils and contamination of waters, aquatic biota, and crops. As human exposure to chlordecone is mainly due to food contamination, early research was focused on chlordecone transfer to crops. Field trials were conducted to investigate chlordecone contamination of yam, sweet potato, turnip, and radish grown on a Ferralic Nitisol polluted by chlordecone. We also carried out trials on yam, courgette, and tomato under greenhouse conditions with homogenized Andosol and Nitisol, polluted by chlordecone to various extents. Our results indicated that i) all tubers were contaminated in accordance with the chlordecone content of the soils; ii) the plant contamination capacity of the Nitisol was greater than that of the Andosol; and iii) whatever the soil type, tuber contamination was related to the soil volumetric content of dissolved chlordecone. Nevertheless, no tubers showed sufficient chlordecone uptake for efficient soil decontamination by means of plant extraction. Soil contact accounted for most of the root crop contamination, which was inversely proportional to the tuber size. Internal transfer might also increase root crop contamination when the root central cylinder contained raw sap flow, as in the case of turnip or radish. Courgette fruits showed high contamination without soil contact. Thus, further research is needed to explore the pattern of both below- and aboveground plant chlordecone contamination and assess the hypothesis of its correlation with sap flow. Finally, we used our results to build a decisionmaking tool for farmers, relating soil pollution with the maximal contamination of the harvested organs to predict crop contamination and thus assisting farmers in making crop choices at planting in order to conform with the European Union's regulations.展开更多
The increased use of pesticides in crop production, especially in Santa, has left consumers with great fear and uncertainty regarding the fate of residues after consumption in the human body. This study was aimed at p...The increased use of pesticides in crop production, especially in Santa, has left consumers with great fear and uncertainty regarding the fate of residues after consumption in the human body. This study was aimed at performing a multi-residue analysis of crop samples to detect and quantify pesticide residues present, and thus determine their level of contamination. Twelve (12) crop samples (4 samples each of Solanum tuberosum (Irish potato), Solanum lycopersicum (tomato), Capsicum annum (sweet pepper) and Apium graveolens (celery)), were randomly collected from four villages in Santa. The samples were analyzed using the QuEChERS Buffered AOAC 2007.01 method. The results showed the presence of pesticide residues in 58.3% of the samples. Cypermethrin and chlorpyrifos insecticides were detected, though cypermethrin was found in traces. After quantification, the concentration of chlorpyrifos was determined to be far above the CODEX Maximum Residue Limits (MRLs) in 28.6% of the samples. Samples with this high concentration of chlorpyrifos were: tomato from Pinyin and Baligham (2.0 and 1.8 μg/g respectively), whereas the Codex MRLs for tomato is 1.0 μg/g. This study raised concerns on the contamination of some garden crops by pesticide residues and calls for the assessment of the health situation of consumers and the analysis of pesticide residues in drinking water resources in this area.展开更多
The North China Plain,where summer corn(Zea mays L.)and winter wheat(Triticum aestivum L.)are the major crops grown,is a major agricultural area in China.Permeable soils make the region susceptible to groundwater poll...The North China Plain,where summer corn(Zea mays L.)and winter wheat(Triticum aestivum L.)are the major crops grown,is a major agricultural area in China.Permeable soils make the region susceptible to groundwater pollution by NO_3-N,which is applied to fields in large amounts of more than 400 kg NO_3-N ha^(-1)as fertilizer.A field experiment was established in 2002 to examine the relationship among N fertilization rate,soil NO_3-N,and NO_3-N groundwater contamination.Two adjacent fields were fertilized with local farmers' N fertilization rate(LN)and double the normal application rate(HN),respectively,and managed under otherwise identical conditions.The fields were under a traditional summer corn/winter wheat rotation.Over a 22-month period,we monitored NO_3-N concentrations in both bulk soil and soil pore water in 20-40 cm increments up to 180 cm depth.We also monitored NO_3-N concentrations in groundwater and the depth of the groundwater table.No significant differences in soil NO_3-N were observed between the LN and HN treatment.We identified NO_3-N plumes moving downward through the soil profile.The HN treatment resulted in significantly higher groundwater NO_3-N,relative to the LN treatment,with groundwater NO_3-N consistently exceeding the maximum safe level of 10 mg L^(-1),but groundwater NO_3-N above the maximum safe level was also observed in the LN treatment after heavy rain.Heavy rain in June,July,and August 2003 caused increased NO_3-N leaching through the soil and elevated NO_3-N concentrations in the groundwater.Concurrent rise of the groundwater table into NO_3-N- rich soil layers also contributed to the increased NO_3-N concentrations in the groundwater.Our results indicate that under conditions of average rainfall,soil NO_3-N was accumulated in the soil profile.The subsequent significantly higher- than-average rainfalls continuously flushed the soil NO_3-N into deeper layers and raised the groundwater table,which caused continuous groundwater contamination with NO_3-N.The results suggest that under common farming practices in the North China Plain,groundwater contamination with NO_3-N was likely,especially during heavy rainfalls,and the degree of groundwater contamination appeared to be proportional to the N application rates.Decreasing fertilization rates, splitting fertilizer inputs,and optimizing irrigation scheduling had potential to reduce groundwater NO_3-N contamination.展开更多
Mycotoxins are the most frequently occurring natural contaminant in food and feed.Their occurrence in crops and animal feed represents an enormous challenge,particularly for livestock farmers in terms of increased pro...Mycotoxins are the most frequently occurring natural contaminant in food and feed.Their occurrence in crops and animal feed represents an enormous challenge,particularly for livestock farmers in terms of increased production costs,reduced animal performance and profitability.This study investigates the scale of emerging mycotoxins contamination of crops and animal feeds globally,and evaluates their impacts on the health and performance of livestock,especially when they co-occur alongside regulated mycotoxins.Emerging mycotoxins including nivalenol,enniatins,beauvericin,diacetoxyscirpenol,fusaric acid,patulin,moniliformin and sterigmatocystin were found to be the most prevalent contaminants of cereals and other feed commodities worldwide.The pooled mean levels for beauvericin,nivalenol,enniatins,moniliformin,sterigmatocystin,diacetoxyscirpenol,fusaric acid,and patulin were 386,421,7,854,204,136,126,370 and 138 mg/kg,respectively.In terms of toxicity,co-occurrence of emerging mycotoxins with each other and also with regulated mycotoxins profoundly impacts livestock performance,even at low levels.Therefore,there is a need for cumulative risk assessments to evaluate the health risks associated with simultaneous exposure to emerging and regulated mycotoxins and also to develop effective mitigation strategies.展开更多
The distribution of radioactive pollutants, such as ^(222)Rn, U, Th and ^(226)Ra in the air, sur- face waters, soils and crops around the Lincang uranium mine, Yunnan Province, China, is studied The mechanical, geoche...The distribution of radioactive pollutants, such as ^(222)Rn, U, Th and ^(226)Ra in the air, sur- face waters, soils and crops around the Lincang uranium mine, Yunnan Province, China, is studied The mechanical, geochemical and biogeochemical processes responsible for the transport and fate of the radioactive elements are discussed based on the monitoring data. The pollutants con- centrations of effluents from the mine tunnels were dependent on pH and SO_4^(2-) which were con- trolled by biochemical oxidation of sulfide in the ore/host rocks. Radon anomalies in air reached 4 km from the tailings pile depending on radon release from the site, topography and climate. ^(238)U and ^(226)Ra abnormities in stream sediments and soil were 40-90 cm deep and 790-800 m away downstream. Anomalies of radioactive contaminants of surface watercourses extended 7.5-13 km from the discharge of effluents of the site mainly depending on mechanical and chemical proc- esses. There were about 2.86 ha rice fields and 1.59 km stream sediments contaminated. Erosion of tailings and mining debris with little or no containment or control accelerated the contamination processes.展开更多
Heavy metal(loid)accumulation in agricultural soils is a threat to the soil capacity,quality,and productivity.It also increases human exposure to heavy metal(loid)s via consumption of contaminated plant-based foods.Th...Heavy metal(loid)accumulation in agricultural soils is a threat to the soil capacity,quality,and productivity.It also increases human exposure to heavy metal(loid)s via consumption of contaminated plant-based foods.The detrimental effects of soil contamination also deteriorate the environment of plants and animals.For sustainable agriculture,therefore,the soil must be protected from toxic levels of heavy metal(loid)s.Studies on heavy metal(loid)balances in agricultural soils are important in predicting future risks to sustainable production from agro-ecological zones and human exposure to heavy metal(loid)s.The latest and continuous indexing of the problem seems a prerequisite for sustainable agriculture.This review provides some background information and then summarizes key methodological approaches for studies on indexing and balance of heavy metal(loid)s in agricultural soils.In the end,important soil and health indices are explained that may be useful in understanding the extent of the problem.The provided information would contribute to sustainable heavy metal(loid)management in the agricultural soils,high crop production,better soil protection,and ultimately to human health.展开更多
文摘Studies on peri urban farming in Zambia have not adequately tackled the issues pertaining to heavy metal contaminated wastewater irrigation farming. The study investigated heavy metal contamination of water, soils and crops at two peri urban areas in Zambia. Two study sites were New Farm Extension in Mufulira Town in the Copperbelt Province and Chilumba Gardens in Kafue Town in Lusaka Province. The heavy metals investigated were lead, copper, cobalt, nickel and chromium. These heavy metals were found to be higher than acceptable limits in wastewater used to irrigate crops and there are potential human health risks associated with consumption of heavy metal contaminated food crops which have implications on the livelihoods of people. Samples of water, soil and crops were collected and analysed for lead (Pb), copper (Cu), chromium (Cr), cobalt (Co) and nickel (Ni) using the Atomic Absorption Spectrometer (AAS). The data on heavy metals was analysed using mean, standard error and T-test. The results indicated that the levels of heavy metals in wastewater, soil and food crops were above acceptable limits at two study sites. It can be concluded that there was heavy metal contamination of wastewater, soil and food crops at the two peri-urban areas in Zambia. The study highlighted the actual levels of heavy metal contaminant uptake in food crops consumed by the peri urban population. The information from this study can be used by the relevant authorities to develop appropriate measures for monitoring and control of heavy metal contamination in wastewater irrigation farming systems in peri urban areas inZambia.
文摘Mycotoxins are secondary metabolites produced by several fungal species and molds.Under favorable conditions like high temperature and moisture,they contaminate a large number of food commodities and regional crops during pre and post-harvesting.Aflatoxin is the main mycotoxin that harm animal and human health due to its carcinogenic nature.Aflatoxins are mainly released by Aspergillus flavus and Aspergillus parasiticus.AFB1 constitutes the most harmful type of aflatoxins and is a potent hepato-carcinogenic,mutagenic,teratogenic and it suppresses the immune system.To maintain food safety and to prevent aflatoxin contamination in food crops,combined approaches of using resistant varieties along with recommended farming practices should be followed.This review concentrates on various aspects of mycotoxin contamination in crops and recent methods to prevent or minimize the contamination.
文摘There are two pathways for nitrate to enter into human body: drinking water and food. Therefore, nitrate contamination of drinking water and agricultural crops is of particular interest to governments and the general public owing to the possible implications for health. This work investigated nitrate contents in various crops and in different parts of each crop and in drinking water as well in the Zhangye Basin, Northwest China. It provided evidence of severe nitrate contamination of drinking water, especially, in vegetable-growing villages. As to the nitrate contamination of crops, the present study revealed that all sampled crops adjust their nitrate distributions in a way that the edible parts contain much less nitrate than non-edible parts except lettuce. The nitrate content in the edible root of lettuce reached up to 5900 mg/kg exceeding the limit set by the European Commission.
基金Supported by the Ministry of Ecology and Sustainable Development and the Ministry of Agriculture and Food,France,the French National Agency of Research,and the French National Chlordecone Action Plan
文摘Chlordecone, one of the most persistent organochlorine pesticides, was applied between 1972 and 1993 in banana fields in the French West Indies, which results in long-term pollution of soils and contamination of waters, aquatic biota, and crops. As human exposure to chlordecone is mainly due to food contamination, early research was focused on chlordecone transfer to crops. Field trials were conducted to investigate chlordecone contamination of yam, sweet potato, turnip, and radish grown on a Ferralic Nitisol polluted by chlordecone. We also carried out trials on yam, courgette, and tomato under greenhouse conditions with homogenized Andosol and Nitisol, polluted by chlordecone to various extents. Our results indicated that i) all tubers were contaminated in accordance with the chlordecone content of the soils; ii) the plant contamination capacity of the Nitisol was greater than that of the Andosol; and iii) whatever the soil type, tuber contamination was related to the soil volumetric content of dissolved chlordecone. Nevertheless, no tubers showed sufficient chlordecone uptake for efficient soil decontamination by means of plant extraction. Soil contact accounted for most of the root crop contamination, which was inversely proportional to the tuber size. Internal transfer might also increase root crop contamination when the root central cylinder contained raw sap flow, as in the case of turnip or radish. Courgette fruits showed high contamination without soil contact. Thus, further research is needed to explore the pattern of both below- and aboveground plant chlordecone contamination and assess the hypothesis of its correlation with sap flow. Finally, we used our results to build a decisionmaking tool for farmers, relating soil pollution with the maximal contamination of the harvested organs to predict crop contamination and thus assisting farmers in making crop choices at planting in order to conform with the European Union's regulations.
文摘The increased use of pesticides in crop production, especially in Santa, has left consumers with great fear and uncertainty regarding the fate of residues after consumption in the human body. This study was aimed at performing a multi-residue analysis of crop samples to detect and quantify pesticide residues present, and thus determine their level of contamination. Twelve (12) crop samples (4 samples each of Solanum tuberosum (Irish potato), Solanum lycopersicum (tomato), Capsicum annum (sweet pepper) and Apium graveolens (celery)), were randomly collected from four villages in Santa. The samples were analyzed using the QuEChERS Buffered AOAC 2007.01 method. The results showed the presence of pesticide residues in 58.3% of the samples. Cypermethrin and chlorpyrifos insecticides were detected, though cypermethrin was found in traces. After quantification, the concentration of chlorpyrifos was determined to be far above the CODEX Maximum Residue Limits (MRLs) in 28.6% of the samples. Samples with this high concentration of chlorpyrifos were: tomato from Pinyin and Baligham (2.0 and 1.8 μg/g respectively), whereas the Codex MRLs for tomato is 1.0 μg/g. This study raised concerns on the contamination of some garden crops by pesticide residues and calls for the assessment of the health situation of consumers and the analysis of pesticide residues in drinking water resources in this area.
基金Project supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(No.kzc x2-yw-406)the National Basic Research Program of China(No.2005CB121103).
文摘The North China Plain,where summer corn(Zea mays L.)and winter wheat(Triticum aestivum L.)are the major crops grown,is a major agricultural area in China.Permeable soils make the region susceptible to groundwater pollution by NO_3-N,which is applied to fields in large amounts of more than 400 kg NO_3-N ha^(-1)as fertilizer.A field experiment was established in 2002 to examine the relationship among N fertilization rate,soil NO_3-N,and NO_3-N groundwater contamination.Two adjacent fields were fertilized with local farmers' N fertilization rate(LN)and double the normal application rate(HN),respectively,and managed under otherwise identical conditions.The fields were under a traditional summer corn/winter wheat rotation.Over a 22-month period,we monitored NO_3-N concentrations in both bulk soil and soil pore water in 20-40 cm increments up to 180 cm depth.We also monitored NO_3-N concentrations in groundwater and the depth of the groundwater table.No significant differences in soil NO_3-N were observed between the LN and HN treatment.We identified NO_3-N plumes moving downward through the soil profile.The HN treatment resulted in significantly higher groundwater NO_3-N,relative to the LN treatment,with groundwater NO_3-N consistently exceeding the maximum safe level of 10 mg L^(-1),but groundwater NO_3-N above the maximum safe level was also observed in the LN treatment after heavy rain.Heavy rain in June,July,and August 2003 caused increased NO_3-N leaching through the soil and elevated NO_3-N concentrations in the groundwater.Concurrent rise of the groundwater table into NO_3-N- rich soil layers also contributed to the increased NO_3-N concentrations in the groundwater.Our results indicate that under conditions of average rainfall,soil NO_3-N was accumulated in the soil profile.The subsequent significantly higher- than-average rainfalls continuously flushed the soil NO_3-N into deeper layers and raised the groundwater table,which caused continuous groundwater contamination with NO_3-N.The results suggest that under common farming practices in the North China Plain,groundwater contamination with NO_3-N was likely,especially during heavy rainfalls,and the degree of groundwater contamination appeared to be proportional to the N application rates.Decreasing fertilization rates, splitting fertilizer inputs,and optimizing irrigation scheduling had potential to reduce groundwater NO_3-N contamination.
基金supported by Bualuang Chair Professor Fund(contract number TUBC 08/2022)Thailand Science Research and Innovation Fundamental Fund fiscal year 2023(Project no.4182267).
文摘Mycotoxins are the most frequently occurring natural contaminant in food and feed.Their occurrence in crops and animal feed represents an enormous challenge,particularly for livestock farmers in terms of increased production costs,reduced animal performance and profitability.This study investigates the scale of emerging mycotoxins contamination of crops and animal feeds globally,and evaluates their impacts on the health and performance of livestock,especially when they co-occur alongside regulated mycotoxins.Emerging mycotoxins including nivalenol,enniatins,beauvericin,diacetoxyscirpenol,fusaric acid,patulin,moniliformin and sterigmatocystin were found to be the most prevalent contaminants of cereals and other feed commodities worldwide.The pooled mean levels for beauvericin,nivalenol,enniatins,moniliformin,sterigmatocystin,diacetoxyscirpenol,fusaric acid,and patulin were 386,421,7,854,204,136,126,370 and 138 mg/kg,respectively.In terms of toxicity,co-occurrence of emerging mycotoxins with each other and also with regulated mycotoxins profoundly impacts livestock performance,even at low levels.Therefore,there is a need for cumulative risk assessments to evaluate the health risks associated with simultaneous exposure to emerging and regulated mycotoxins and also to develop effective mitigation strategies.
基金supported by the National Natural Science Foundation of China(Grant No.49832005)the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of Ministry of Education,China.
文摘The distribution of radioactive pollutants, such as ^(222)Rn, U, Th and ^(226)Ra in the air, sur- face waters, soils and crops around the Lincang uranium mine, Yunnan Province, China, is studied The mechanical, geochemical and biogeochemical processes responsible for the transport and fate of the radioactive elements are discussed based on the monitoring data. The pollutants con- centrations of effluents from the mine tunnels were dependent on pH and SO_4^(2-) which were con- trolled by biochemical oxidation of sulfide in the ore/host rocks. Radon anomalies in air reached 4 km from the tailings pile depending on radon release from the site, topography and climate. ^(238)U and ^(226)Ra abnormities in stream sediments and soil were 40-90 cm deep and 790-800 m away downstream. Anomalies of radioactive contaminants of surface watercourses extended 7.5-13 km from the discharge of effluents of the site mainly depending on mechanical and chemical proc- esses. There were about 2.86 ha rice fields and 1.59 km stream sediments contaminated. Erosion of tailings and mining debris with little or no containment or control accelerated the contamination processes.
基金support from the Higher Education Commission,Islamabad(Pakistan)to conduct related research experiments in Pakistan。
文摘Heavy metal(loid)accumulation in agricultural soils is a threat to the soil capacity,quality,and productivity.It also increases human exposure to heavy metal(loid)s via consumption of contaminated plant-based foods.The detrimental effects of soil contamination also deteriorate the environment of plants and animals.For sustainable agriculture,therefore,the soil must be protected from toxic levels of heavy metal(loid)s.Studies on heavy metal(loid)balances in agricultural soils are important in predicting future risks to sustainable production from agro-ecological zones and human exposure to heavy metal(loid)s.The latest and continuous indexing of the problem seems a prerequisite for sustainable agriculture.This review provides some background information and then summarizes key methodological approaches for studies on indexing and balance of heavy metal(loid)s in agricultural soils.In the end,important soil and health indices are explained that may be useful in understanding the extent of the problem.The provided information would contribute to sustainable heavy metal(loid)management in the agricultural soils,high crop production,better soil protection,and ultimately to human health.
