Sewage Farming Research Articles

Sewage Water Use in Crop Production and Its Effect on Physico-Chemical and Biological Properties of Soil: A Review

The availability of freshwater for irrigation is dwindling, prompting the need for innovative solutions to tackle this critical issue. This research delves into comparing sewage water with fresh water, recognizing the immense volume of wastewater generated daily due to rapid population growth and industrial expansion. The current state of sewage water in India presents a formidable challenge, highlighting the imperative for proactive management strategies moving forward. The study explores methods to harness sewage water for agricultural use, aiming to enhance productivity while acknowledging the global significance of wastewater management. Sewage water composition varies depending on local industrial activities, often containing higher levels of nutrients like nitrogen, phosphorus, potassium, organic carbon, micronutrients, and soil microbial content compared to regular water sources. Utilizing sewage water for irrigation can positively impact soil chemistry and fertility, although it may increase electrical conductivity, albeit usually within acceptable limits to mitigate soil salinity risks. However, sewage water typically contains elevated concentrations of heavy metals such as Cadmium, Chromium, Lead, and Nickel, posing potential hazards to soil and plant health if surpassing safety thresholds. Continuous use of sewage water may exacerbate the accumulation of these hazardous metals, posing risks to both soil quality and human health. Nonetheless, during periods of water scarcity crucial for crop growth, sewage water emerges as a vital resource, potentially saving agricultural productivity. In this context, sewage farming emerges as a promising approach to alleviate the demand for freshwater while addressing wastewater challenges. Embracing sewage water for irrigation holds the promise of significant advancements in curbing wastewater proliferation, underscoring its role as a sustainable solution for agricultural water requirements.

Ostracoda and Foraminifera as bioindicators of (aquatic) pollution in the protected area of uMlalazi estuary, South Africa

To mitigate ecological and health risks, implementing a comprehensive multidisciplinary monitoring strategy is imperative. This approach aims to effectively identify and record potential declines in water quality and ecological conditions. Utilizing cost-effective and efficient monitoring tools is crucial, especially for developing nations. Despite the previously reported uMlalazi River's pristine status within a protected natural reserve at South Africa's eastern coast, our findings challenge the assumption of its cleanliness, emphasizing the need for ongoing proactive monitoring. Here we reassess the pollution levels and ecological status of aquatic life of the river, and use this to enhance the indicator value of microfauna in South Africa. We analysed 25 surface sediment samples from the uMlalazi estuary, covering a salinity range from oligohaline to euhaline, with a focus on marginal marine Ostracoda and Foraminifera as potential indicators. All samples contained Ostracoda and Foraminifera, with the exception of two. Among the identified ostracod species, there were 17 species belonging to 14 genera. Typical taxa are the brackish water species Perissocytheridea estuaria, Sulcostocythere knysnaenis, and Australoloxoconcha favornamentata. We identified 19 Foraminifera species from 16 genera, with dominant taxa such as Ammonia sp., Quinqueloculina sp., and Miliolinella sp. Three distinct assemblages were observed: A) Ammonia sp. and Quinqueloculina sp., with very low diversity and abundances in general, located along the river course at stations exceeding Pollution Load Index (PLI), which indicates deterioration of sites quality; B) Ammonia sp., Quinqueloculina sp., and Sulcostocythere knysnaenis associated with higher salinity and lower PLI; C) Ammonia sp., Quinqueloculina agglutinans, and Cribroelphidium articulatum located in mudflats with minimal PLI. Our findings align with the commonly observed diversity trend, which indicates reduced species diversity corresponding to elevated pollution levels. Notably, the examined samples revealed a range of Foraminiferal Abnormality Index (FAI) up to 23%, exhibiting anomalies such as multiple tests, changes in coiling, and abnormal chamber shapes. Geochemical analysis indicates that the catchment is subjected to substantial anthropogenic pressure, as evidenced by elevated concentrations of heavy metals, sulphur, and microplastic. Sugarcane farming, urban sewage, titanium mining, and fish farming are the primary sources of pollution in the catchment area. Ongoing investigations in South African estuaries are expanding our dataset and will contribute to a better understanding of the species-specific responses of Ostracoda and Foraminifera to anthropogenic pressure.

Evaluating Effects of Nitrogen and Phosphorus Discharges under Different Reduction Scenarios: A Case of Chaohu Lake Basin, China

Determining the amount of nitrogen (N) and phosphorus (P) discharged into lakes and assessing the effectiveness of reduction measures in a basin that involve the interaction of multiple factors are still daunting challenges. In this study, the random forest (RF) model was employed to simulate the impact of controlling measures on the amount of N and P discharged in 2025 under seven specific reduction scenarios. Discharged N and P decreased in the basin by 23.38% and 31.69% from 2011 to 2020, respectively. The N and P nutrient discharge intensities were significantly higher in the western part of the basin (13.31 kg·ha−1·a−1 and 1.34 kg·ha−1·a−1) than those in the eastern region (10.24 kg·ha−1·a−1 and 0.74 kg·ha−1·a−1). Fertilizer runoff (N: 34.72%, 5934.49 t; P: 13.60%, 199.76 t), domestic sewage (N: 29.14%, 4009.27 t; P: 34.84%, 496.59 t), and livestock farming (N: 15.11%, 2657.50 t; P: 40.05%, 616.05 t) were the key sources of N and P. The RF model shows that (R2 > 0.994, p < 0.01) the multi-factor reduction effect is the best, and under this discharge reduction effect, the amount of N and P discharged in 2025 are expected to decrease by 13.79% and 19.42%, respectively, compared with those in 2020. In addition, different key sources in sub-basins might lead to regional differences in the discharge reduction effects of various measures. Ultimately, we recommend that the synergistic treatment of point and non-point sources, using treatments with multiple measures, should be implemented in different regions to reduce the amount of N and P discharged in the Chaohu Lake Basin.

Red Amaranth (Amaranthus tricolor L.) Irrigated with Domestic Sewage Wastewater as a Source of Irrigation: Environmental Food Security and Safety Assessment Perspectives through Acute and Sub- Acute Toxicity Study

Water deficiency is one of the main factors for limiting sustainable agricultural development in most arid and semi-arid regions. There is a gradual decline in the availability of fresh water to be used for irrigation in developing countries like India. Sewage farming is quite common in all urban areas in India. The effect of its direct and long-term use for irrigation needs a thorough study. However, there is increasing concern about food safety and health risks, hence, a case study was undertaken to understand the long-term effect of domestic sewage wastewater irrigation on heavy metal concentrations in soil and plants. The study reveals the mineral and heavy metal composition of irrigated domestic sewage wastewater and it has been compared with the well water irrigated in the rural area, soil parameters and also the mineral and heavy metal composition of a cultivated plant, Amaranthus tricolor L. Transfer factor (TF) was calculated to understand the extent of risk and associated hazard due to wastewater irrigation and the consequence of heavy metals accumulation in the edible portion of experimented vegetables. The present study was carried out to assess the potential toxicity of acetone extract of A. tricolor with some essential parameters such as haematological and biochemical parameters, liver and kidney weight and their histopathological study. After conducting in vivo acute and subchronic toxicity experiments using the rat model, there was no toxicity or mortality observed between domestic sewage water and well water irrigated to red amaranth, A. tricolor.

Mercury Sources, Emissions, Distribution and Bioavailability along an Estuarine Gradient under Semiarid Conditions in Northeast Brazil

In the semiarid coast of northeast Brazil, climate change and changes in land use in drainage basins affect river hydrodynamics and hydrochemistry, modifying the estuarine environment and its biogeochemistry and increasing the mobilization of mercury (Hg). This is particularly relevant to the largest semiarid-encroached basin of the region, the Jaguaribe River. Major Hg sources to the Jaguaribe estuary are solid waste disposal, sewage and shrimp farming, the latter emitting effluents directly into the estuary. Total annual emission reaches 300 kg. In that estuary, the distribution of Hg in sediment and suspended particulate matter decreases seaward, whereas dissolved Hg concentrations increase sharply seaward, suggesting higher mobilization at the marine-influenced, mangrove-dominated portion of the estuary, mostly in the dry season. Concentrations of Hg in rooted macrophytes respond to Hg concentrations in sediment, being higher in the fluvial endmember of the estuary, whereas in floating aquatic macrophytes, Hg concentrations followed dissolved Hg concentrations in water and were also higher in the dry season. Animals (fish and crustaceans) also showed higher concentrations and bioaccumulation in the marine-influenced portion of the estuary. The variability of Hg concentrations in plants and sediments agrees with continental sources of Hg. However, Hg fractionation in water and contents in the animals respond to higher Hg availability in the marine-dominated end of the estuary. The results suggest that the impact of anthropogenic sources on Hg bioavailability is modulated by regional and global environmental changes and results from a conjunction of biological, ecological and hydrological characteristics. Finally, increasing aridity due to global warming, observed in northeast Brazil, as well as in other semiarid littorals worldwide, in addition to increased water overuse, augment Hg bioavailability and environmental risk and exposure of the local biota and the tradition of human populations exploiting the estuary's biological resources.

Damage Caused by Sphaeroma to Mangrove Forests in Hainan, Dongzhaigang, China

Xin, K.; Xie, Z.; Zhong, C.; Sheng, N.; Gao, C., and Xiao, X., 2020. Damage caused by Sphaeroma to mangrove forests in Hainan, Dongzhaigang, China. Journal of Coastal Research, 36(6), 1197–1203. Coconut Creek (Florida), ISSN 0749-0208.Sphaeroma population expansion has become a serious threat to mangroves in China over recent years. This study investigated the distribution of Sphaeroma damaged forests in Hainan, Dongzhaigang, China, using RS data and field investigations. The damage to mangroves caused by Sphaeroma was categorized into three grades that were based on the death rate, damage rate, and recovery rate after a typhoon. The grades were seriously damaged forest, moderately damaged forest, and slightly damaged forest, and 8.18, 230.11, and 125.83 hm2 were covered by the three grades, respectively. The most seriously damaged mangrove species were Bruguiera sexangula, Avicennia marina, and Bruguiera gymnorrhiza. However, many other mangrove species, such as Lumnitzera racemosa, Excoecaria agallocha, and Ceriops tagal, were nearly free from Sphaeroma. The integrated disaster index results, which were based on 59 different mangrove communities in the study area, showed that the communities mainly comprised B. sexangula and Bruguieras var. rhinochopetala, Sonneratia caseolaris, and Sonneratia apetala. The B. sexangula and B. gymnorrhiza and the Kandelia obovata communities were more seriously damaged than other communities. The distribution characteristics of the damaged mangroves indicated that communities that contained larger individuals and were closer to tidal creeks were more likely to be destroyed. Finally, the impacts of aquaculture sewage and duck farming may be driving Sphaeroma population expansion, and the results strongly suggested that dynamic monitoring of the Sphaeroma population after a typhoon should occur.

Effect of domestic sewage wastewater irrigation on nutritional and nutraceutical perspectives of Eleusine coracana and Zea mays (raw and processed) from selected semi-urban and rural areas of Coimbatore, Tamil Nadu

Rapid growth of the urban population, particularly in developing countries, places an enormous pressure on water. Sewage farming is common in all urban areas in India. This study is an attempt to evaluate the effect of diluted sewage wastewater irrigation on cultivation of Eleusine coracana and Zea mays from selected semi-urban and rural areas of Coimbatore, Tamil Nadu. For this, parameters analyzed were water/soil quality, crop quality, and mineral analysis including heavy metal composition and in vitro antioxidant potential. From the results, the physicochemical parameters of both rural and semi-urban wastewater samples are within the permissible limits according to the WHO. In mineral analysis, the heavy metals such as Pb, Fe, and Zn are high in all samples and Ni, Cr, and Cu are within the permissible limits in rural samples but slightly high in semi-urban samples. The proximate composition provides general overview of the nutritional value of a food. E. coracana and Z. mays samples collected from rural area show adequate mineral profile required for growth and nutrition. Both the samples show significant antioxidant values significant at p < 0.05. The results demonstrated that the diluted sewage wastewater has physicochemical properties for safe irrigation. Micronutrient and heavy metal contents in the plant samples were not extremely high and were within the range of FAO/WHO standards.

Comparative Study of Different Sewage Farming on Soil Quality

Comparative Study of Different Sewage Farming on Soil Quality

Comparative Study of Different Sewage Farming on Soil Quality: A Review

Comparative Study of Different Sewage Farming on Soil Quality: A Review

Tracking Nitrogen Source Using δ15N Reveals Human and Agricultural Drivers of Seagrass Degradation across the British Isles.

Excess nutrients shift the ecological balance of coastal ecosystems, and this eutrophication is an increasing problem across the globe. Nutrient levels may be routinely measured, but monitoring rarely attempts to determine the source of these nutrients, even though bio-indicators are available. Nitrogen stable isotope analysis in biota is one such bio-indicator, but across the British Isles, this is rarely used. In this study, we provide the first quantitative evidence of the anthropogenic drivers of reduced water quality surrounding seagrass meadows throughout the British Isles using the stable nitrogen isotope δ15N. The values of δ15N ranged from 3.15 to 20.16‰ (Mean ± SD = 8.69 ± 3.50‰), and were high within the Thames Basin suggesting a significant influx of urban sewage and livestock effluent into the system. Our study provides a rapid ‘snapshot’ indicating that many seagrass meadows in the British Isles are under anthropogenic stress given the widespread inefficiencies of current sewage treatment and farming practices. Ten of the 11 seagrass meadows sampled are within European marine protected sites. The 10 sites all contained seagrass contaminated by nutrients of a human and livestock waste origin leading us to question whether generic blanket protection is working for seagrasses in the United Kingdom. Infrastructure changes will be required if we are to develop strategic wastewater management plans that are effective in the long-term at protecting our designated Special Areas of Conservation. Currently, sewage pollution is a concealed issue; little information exists and is not readily accessible to members of the public.

Ecological risk assessment of trace metals in the surface sediments of the Persian Gulf and Gulf of Oman: Evidence from subtropical estuaries of the Iranian coastal waters

This study aimed to investigate the ecological risk assessment of Khamir, Tiyab, and Jagin estuaries and the impact of anthropogenic activities on these ecosystems during a one-year study period (April 2015 to March 2016) using trace metals as pollution indices. The sediment samples were collected from nine sampling stations, following a gradient of contamination from the industrial wastewater and shrimp farming effluents to the less impacted stations. Pollution indices (i.e. PERI and PLI) were applied to ascertain the sediment quality. Based on pollution indices, the overall pattern of environmental quality status demonstrated that industrial sewage and shrimp farming effluents are major sources of pollution in the Khamir and Tiyab estuaries, respectively. The sediments in the most stations in studied coastal ecosystems of Iran posed moderate or considerable ecological risk. Results from this study showed that Zn, Pb, Cu, and Cd were mostly derived from anthropogenic activities such as domestic sewage and industrial effluents. Also, the findings of this study revealed that the pollution indices are suitable for evaluating the environmental situation of coastal ecosystems and the separation of areas with less impacted by human activities from areas affected by these activities and could be used as a robust management tool for monitoring programs in coastal areas. Altogether, these findings could be useful in providing more effective and targeted strategies of development better management practices for coastal areas.

HEAVY METAL DETECTION FROM SEWAGE IRRIGATED SOIL BESIDE RAILWAY TRACKS IN MUMBAI

There are more than 100 local train stations in Mumbai and suburban areas which are connected to each other through railway comprising 4 major lines. Each route contains slow and fast tracks running. On the adjacent side of these routes are small patches of land which are used for cultivation. The railway authorities give these lands for farming of some leafy and non-leafy vegetable crops. Majority of these lands are irrigated by the open sewage lines which run besides and parallel to the railway tracks and they bring many unwanted chemicals which are absorbed by plants to more or less extent. The water in these sewerlines comes from domestic, commercial and other sources. The present study deals with quantification of Pb, Zn, Cd, Hg, Ar and Cu from soil sample using laboratory methods. The results indicated a low to medium level of pollution of these in soils, except some of the areas where it is high. The Pb, Ar and Cu were common pollutants near many stations and occur in comparable amount whereas Cd and Zn occur near fewer stations and also in less to medium quantity and Hg contents were found to be the least. The results indicate that though the sewage water can be used for such sewage farming, the water quality should be monitored continuously for heavy metals and other form of pollutants to ensure safety for vegetable consumption.

Water quality assessment and source identification of water pollution in the Banchengzi reservoir, Beijing, China

Water quality in the Banchengzi reservoir in Beijing has been deteriorating year by year, and it was embodied by increasing concentrations of COD and stable but high levels of total nitrogen. In order to identify the causes and to formulate a strategy for pollution prevention and control, we examined the temporal and spatial variations of water pollution and carried out source identification studies. Routine monthly monitoring data for seven water quality and six hydro-meteorological variables of the Banchengzi reservoir from 2007 to 2012 were analyzed by statistical techniques, including correlation analysis and principle component analysis. In addition, water samples at six different sites in the reservoir were collected and analyzed to investigate the spatial variation of water quality and to further identify the water pollution sources by UV–vis spectroscopy, three-dimensional excitation-emission matrix spectroscopy, and nitrogen stable isotope (δ15N) analysis. The results revealed that dissolved organic matter and nitrogen were the main pollutants and were principally derived from anthropogenic point source pollution in the upper areas, which included domestic sewage and livestock farming. We speculated that the biodegradable organic pollutants from sewage were degraded to form soluble microbial products (SMP) by aerobic microorganisms and that nitrogen pollutants were mostly transformed to nitrate by nitrification. These SMP, nitrate, and other refractory pollutants were carried by the upper stream flowing into the Banchengzi reservoir, where it accumulated. Effective control of point source pollution and upper river ecological restoration should be done to improve the water quality and protect the reservoir.

Management Of Sewage Farming In Arid Region: Egyptian Experience

Ponte Academic JournalMar 2016, Volume 72, Issue 3 Management Of Sewage Farming In Arid Region: Egyptian ExperienceAuthor(s): Hussein Abouziena ,M. Saber, E. Hoballah, Wafaa M. Hggag, A. ZaghloulJ. Ponte - Mar 2016 - Volume 72 - Issue 3 doi: 10.21506/j.ponte.2016.3.7 Abstract:Sustainable management of sewage farming is one of the major challenges that Egypt had to deal with in the coming few decades and beyond, as it represents one of the vital environmental issue at political, technical and research levels as well. Sewage farming is a centuries-old practice in Egypt that is now receiving a renewed attention. It started in a desert area east Cairo (El-Gabal El Asfer) since 1930 and extended as time goes on to cover vast areas all over the country. Egypt gained an extensive experience in sewage faring along these decades. The current review article explore this experience gained in the major sewage farms in Egypt located at El-Gabal Al-Asfer, Abu-Rawash and El-Saff, in addition to the current situation of existing lumber forests and sewage farming legislations applied in Egypt. Download full text:Check if you have access through your login credentials or your institution Username Password

Evaluation of vermifiltration process using natural ingredients for effective wastewater treatment

The present investigation focused on the evaluation of vermifiltration process using different natural ingredients as a media. The vermifilter was evaluated using different natural ingredients viz river bed material, wood coal, glass balls, mud balls and employing Eisenia fetida as an earthworm species. The complete study was carried out for 90 days. The average COD removal for different material i.e. river bed material, wood coal, glass balls and mud balls was found as 72.3, 64.6, 61.5 and 59.8% while average BOD removal was observed as 81.2, 74.5, 72.7 and 70.9%, for respective filter media. Similarly, the total suspended solid removal was observed as 75, 64, 59 and 55%, respectively for above mentioned different media. The river bed material revealed maximum reduction of indicator organisms like total coliform (3.6±0.90 log unit), fecal coliform (3.4±0.67 log unit), fecal streptococci and Escherichia coli (2.5±0.51 log unit). At the end of the run vermicompost obtained through vermifiltration process as a byproduct were found to be rich in nitrate (31.2±5.9mg/L), phosphate (18.1±4.6mg/L) which could be exploited in sewage farming.

Effects of raw and diluted municipal sewage effluent with micronutrient foliar sprays on the growth and nutrient concentration of foxtail millet in southeast Iran

In this study, the effect of irrigation with raw or diluted municipal sewage effluent accompanied by foliar micronutrient fertilizer sprays was examined on the growth, dry matter accumulation, grain yield, and mineral nutrients in foxtail millet plants. The experimental design was a split plot with three irrigation sources: raw sewage, 50% diluted sewage, and well water comprising the main treatments, and four combinations of Mn and Zn foliar sprays as sub-treatments that were applied with four replications. The experiment was conducted in 2009 at the Zabol University research farm in Zabol, south Iran. The applied municipal sewage effluent contained higher levels of micronutrients and macronutrients and exhibited greater degrees of electrical conductivity compared to well water. Because of the small scale of industrial activities in Zabol, the amount of heavy metals in the sewage was negligible (below the limits set for irrigation water in agricultural lands); these contaminants would not be severely detrimental to crop growth. The experimental results indicated that irrigation of plants with raw or diluted sewage stimulates the measured growth and productivity parameters of foxtail millet plants. The concentrations of micronutrients and macronutrients were also positively affected. These stimulations were attributed to the presence of high levels of such essential nutrients as N, P, and organic matter in wastewater. Supplied in sewage water alone, Mn and Zn were not able to raise the productivity of millet to the level obtained using fertilizers at the recommended values; this by itself indicated that additional nutrients from fertilizers are required to obtain higher levels of millet productivity with sewage farming. Despite the differences in nutrient concentrations among the different irrigation water sources, the micronutrient foliar sprays did not affect the concentrations of micronutrients and macronutrients in foxtail millet plants. These results suggested that municipal sewage effluent could be utilized efficiently as an important source of water, and that the nutrients used in growing foxtail millet with sewage water irrigation did not have any significant harmful effect on crop productivity. In contrast, the nutrients proved beneficial to soil fertility and millet productivity and quality.

Soil salinity and sodicity effects of wastewater irrigation in South East Australia

Abstract Although ‘sewage farming’ or wastewater irrigation started in Australia in the latter parts of the 19th century, it was in the late 1960s that a considerable interest was revived in arid and semi-arid parts of the world due to scarcity of alternative water sources and the urgency to increase local food production. The practice has manifold benefits in the form of water conservation, nutrient recycling, surface and ground water pollution prevention. But for arid and semi-arid regions like many parts of Australia, while wastewater irrigation can be an attractive solution to irrigation water problems, it might not be the ideal solution for the common soil types encountered in these regions. Due to characteristic low rainfall, high evaporation and low leaching, these soils tend to have higher salt accumulations. This paper examines the soil salinity and sodicity effects of wastewater irrigation in soil types typical to South Eastern Australia and takes the soils of Western Treatment Plant (WTP) as a case study to highlight these issues.

Chemical, biochemical, and biological impact of untreated domestic sewage water use on Vertisol and its consequences on wheat (Triticum aestivum) productivity

In the peri-urban areas of central India, sewage water is a valuable resource for agricultural production. In this study, impact of domestic sewage water irrigation for 5 years on Vertisol with no previous history of sewage irrigation was investigated in an ongoing field experiment at Bhopal (India) under subtropical monsoon type climate. The wheat (Triticum aestivum) crop was grown during post-rainy winter season with 30 cm of irrigation (groundwater or sewage water) and four nutrient treatments (T(1), 0; T(2), 100%; T(3), 50%; and T(4), 50% of general recommended doses of NPK + FYM at 10 Mg/ha). Results showed that sewage irrigation of about 150 cm over a period of 5 years resulted significant increases in salinity as well as available fractions of N, P, K, and micronutrients, viz., Zn, Fe, and Mn in soils. Carbon and phosphorus applied through sewage water were accumulated more in subsoil layer compared to topmost plough layer. Soil microbiological activity, as indicated by soil respiration, microbial biomass C, as well as dehydrogenase enzyme activity was higher in sewage water-irrigated soils. There was also significant increase in fungal and actinomycetes as well as total coliform population in such soils. Nutrients supplied through sewage water were not able to raise the productivity of wheat to the level that obtained through fertilizers at the recommended level which indicated that additional nutrients through fertilizers are required to obtain higher productivity of wheat under sewage farming. Protein and Zn content in wheat grains were more when the crop was grown with sewage irrigation. Overall results show that except for increase in coliform population, short duration (5 years) of municipal sewage water irrigation did not have any appreciable harmful effect on soil quality as well as crop productivity; rather, it proved beneficial in improving soil fertility, wheat productivity, and produce quality.

Wastewater Quality and the Risk of Intestinal Nematode Infection in Sewage Farming Families in Hyderabad, India

Use of sewage or wastewater in agriculture is becoming increasingly common as a result of a global water scarcity. Intestinal nematode infections have been identified as the main health risk associated with this practice. To protect consumer and farmer health, the World Health Organization (WHO) has established an intestinal nematode water quality standard. However, because of a lack of well-designed studies, the validity of this guideline is questioned. This report presents the findings of a study on the risk of intestinal nematode infections in farming families occupationally exposed to untreated and partially treated wastewater in Hyderabad, India. The study found an increased risk of hookworm (odds ratio [OR] 3.5, 95% confidence interval [CI] = 2.2-5.5), Ascaris lumbricoides (OR = 5.3, 95% CI = 2.0-14), and Trichuris trichiura (OR = 5.6, 95% CI = 1.8-18) infection when untreated wastewater (150 intestinal nematode ova/liter) was used for crop production. Use of partially treated wastewater (28 intestinal nematode ova/liter) was only associated with an increased risk (OR = 3.2, 95% CI = 1.2-8.6) of A. lumbricoides infection. The findings of the study suggest that the current WHO intestinal nematode guideline of 1 ova/liter is sufficient to protect farmer health.

Health effect of human wastes use in agriculture in El Azzouzia (the wastewater spreading area of Marrakesh city, Morocco)

The use of wastewater and excreta in agriculture constitutes an important source of spread Salmonella strains and protozoan infections into the environment. This practice has been used in El Azzouzia (the wastewater-spreading area of Marrakesh city, Morocco) for several years. The available circumstantial evidence gained from epidemiological and microbiological investigations suggests that the use of untreated wastewater causes an excess of protozoan infections among children living in El Azzouzia (72%) compared with those from a control area (45%). The pathogenic protozoan infections observed were giardiasis (39%) and amoebiasis (28%). For Salmonella infection, 21.34% of the exposed children were infected, while this rate did not exceed 1.14% in the control group. The serogroups B and C were the most commonly isolated. The sewage farming children are therefore more exposed to detectable risk from pathogenic micro-organisms than the control children.