A quantitative approach on environment-food nexus: integrated modeling and indices for cumulative impact assessment of farm management practices.

Background: Best management practices (BMPs) are promising solutions that can partially control pollution discharged from farmlands. These strategies, like fertilizer reduction and using filter strips, mainly control nutrient (N and P) pollution loads in basins. However, they have secondary impacts on nutrition production and ecosystem. This study develops a method to evaluate the cumulative environmental impacts of BMPs. It also introduces and calculates food's environmental footprint (FEF) for accounting the total environmental damages per nutrition production. Methods: This study combines the soil and water assessment tool (SWAT) for basin simulation with the indices of ReCiPe, a life cycle impact assessment (LCIA) method. By these means, the effectiveness of BMPs on pollution loads, production yields, and water footprints (WFs) are evaluated and converted as equivalent environmental damages. This method was verified in Zrebar Lake, western Iran. Here, water consumption, as WFs, and eutrophication are the main indices that are converted into equivalent health and ecological impairments. Two methods, entropy and environmental performance index (EPI), are used for weighting normalized endpoints in last step. Results: Results showed that using 25-50% less fertilizer and water for irrigation combined with vegetated filter strips reduce N and P pollution about 34-60% and 8-21%, respectively. These can decrease ecosystem damages by 5-9% and health risks by 7-14%. Here, freshwater eutrophication is a more critical damage in ecosystem. However, using less fertilizer adversely reduces total nutrition production by 1.7-3.7%. It means that BMPs can decline total ecological damages and health risks, which threatens nutrition production. FEF presents a tool to solve this dilemma about the sustainability of BMPs. In the study area, a 4-9% decrease in FEF means that BMPs are more environmental friendly than nutrition menacing. Finally, this study concludes that SWAT-ReCiPe with FEF provides a quantitative framework for environment-food nexus assessment. However, due to the uncertainties, this method is recommended as a tool for comparing management strategies instead of reporting certain values.

Interactive effects of maternal exposure to chemical fertilizer and socio-economic status on the risk of low birth weight.

BACKGROUND: Maternal exposure to chemical fertilizer and disadvantaged maternal socio-economic status (SES) have been found to associate with increased risk of low birth weight (LBW). However, whether the two factors would interact to elevate the risk of LBW remains unknown. The present study aimed to explore the interactive effects of maternal exposure to chemical fertilizer during pregnancy and low SES on the risk of term LBW (tLBW). METHODS: In this population-based case-control study, 179 tLBW cases (birthweight < 2500 g and gestational age ≥ 37 weeks) and 204 controls (birthweight ≥ 2500 g and gestational age ≥ 37 weeks) were chosen from the Perinatal Health Care Surveillance System of Pingding County, Shanxi Province, China between 2007 and 2012. Data on basic socio-demographic, dietary and lifestyle characteristics and environmental exposure were directly extracted from the system. Maternal exposure to chemical fertilizer was measured at both household level and village level. Household-level exposure was indicated by household chemical fertilizer use in farming during pregnancy and the data was collected by trained healthcare workers after the selection of cases and controls in 2013. Village-level exposure was indicated by annual amount of village chemical fertilizer consumption per acre and the data came from the Annals of National Economics Statistics of Pingding County in 2010. Interactions between maternal exposure to chemical fertilizer and SES were assessed in logistic regressions using relative excess risk due to interaction (RERI), which indicates an additive interaction if larger than 0. RESULTS: The combination of low maternal SES and high exposure to village-level chemical fertilizer consumption was associated with increased risk of tLBW (aOR = 2.62, 95%CI: 1.44 ~ 4.77); The combination of low maternal SES and exposure to household chemical fertilizer use was associated with elevated risk of tLBW (aOR = 2.18, 95%CI: 1.24 ~ 3.83). Additive interactions were detected between high exposure to village-level chemical fertilizer consumption and low maternal SES (RERI:1.79, P < 0.001) and between exposure to household chemical fertilizer use and low maternal SES (RERI:0.77, P < 0.05). CONCLUSIONS: Our study suggested negative impacts of potential agricultural pollutants on adverse pregnancy outcomes, especially in disadvantaged socio-economic populations.

Use of raw and composted poultry litter in lettuce produced under field conditions: microbiological quality and safety assessment.

Lettuce (Lactuca sativa L.) constitutes one the most important vegetable crops worldwide. Poultry litter is being applied as an economically suitable alternative to nitrogen fertilizers in lettuce cultivation. However, little is known about the effects of this practice over this fresh product safety that is usually consumed as a salad. The aim of this work was to determine the microbiological quality and the nitrate content in lettuce produced, under field conditions, using either raw or composted poultry litter, coming from the same original batch. Two experiments were conducted in the experimental field of Facultad de Ciencias Agrarias (UNL, Santa Fe, Argentina) to assess the effects of recently extracted poultry litter that consisted of broiler chicken manure plus rice husk, or composted for 12 mo. The application amounts were: 20 T ha-1 (T1); 40 T ha-1 (T2); and no application of manure (T). Increasing the applied quantities had also increased the health risk associated with lettuce consumption, due to higher nitrate levels and microbial contamination. However, these risks were reduced by composting the material. Even when lettuce contamination with faecal bacteria was mainly due to the use of poultry litter, the number and incidence of pathogens were reduced when properly composted manure was applied instead of raw one. Increasing the dose of poultry litter applied also increases the health risk in lettuce. Though, when the material is properly composted, its fertilizing capacity is maintained, giving proper yields with lower nitrate levels and microbial contamination by enterobacteria.

Seafood prices reveal impacts of a major ecological disturbance.

Coastal hypoxia (dissolved oxygen ≤ 2 mg/L) is a growing problem worldwide that threatens marine ecosystem services, but little is known about economic effects on fisheries. Here, we provide evidence that hypoxia causes economic impacts on a major fishery. Ecological studies of hypoxia and marine fauna suggest multiple mechanisms through which hypoxia can skew a population's size distribution toward smaller individuals. These mechanisms produce sharp predictions about changes in seafood markets. Hypoxia is hypothesized to decrease the quantity of large shrimp relative to small shrimp and increase the price of large shrimp relative to small shrimp. We test these hypotheses using time series of size-based prices. Naive quantity-based models using treatment/control comparisons in hypoxic and nonhypoxic areas produce null results, but we find strong evidence of the hypothesized effects in the relative prices: Hypoxia increases the relative price of large shrimp compared with small shrimp. The effects of fuel prices provide supporting evidence. Empirical models of fishing effort and bioeconomic simulations explain why quantifying effects of hypoxia on fisheries using quantity data has been inconclusive. Specifically, spatial-dynamic feedbacks across the natural system (the fish stock) and human system (the mobile fishing fleet) confound "treated" and "control" areas. Consequently, analyses of price data, which rely on a market counterfactual, are able to reveal effects of the ecological disturbance that are obscured in quantity data. Our results are an important step toward quantifying the economic value of reduced upstream nutrient loading in the Mississippi Basin and are broadly applicable to other coupled human-natural systems.

[Gas chromatography-mass spectrometric studies of volatile emissions from plants for the assessment of the effectiveness and chemical safety of the implementation of environment improving phytotechnologies].

The chromato-mass-spectrometric studies of volatile emissions of fresh-cut roses have revealed the persistence of wide range of organic compounds. The most large content was consist of terpene hydrocarbons. The contribution of oxygen-containing components (alcohols, ethers, aldehydes and ketones) varied in wide ranges in dependence on the content of the feeding solution. The significant part of plants ' volatiles has no hygienic norm. Among the substances released into the air space ofpremises with volatile emissions ofplants, a significant part has not hygienic standards. Purposeful change in composition of the mixture of volatile organic compounds released by the plants, in the combination with chemical-analytical control of the content of these substances by gas chromatography-mass spectrometry in terms of ecological and hygienic aspects may be useful in the development, use and determination of the optimal conditions of the implementation of environment improving phytotechnologies and evaluation of the efficacy and safety of their impact on public health.

Radiometric assessment of natural radioactivity levels of agricultural soil samples collected in Dakahlia, Egypt.

Determination of the natural radioactivity has been carried out, by using a gamma-ray spectrometry [NaI (Tl) 3″ × 3″] system, in surface soil samples collected from various locations in Dakahlia governorate, Egypt. These locations form the agriculturally important regions of Egypt. The study area has many industries such as chemical, paper, organic fertilisers and construction materials, and the soils of the study region are used as a construction material. Therefore, it becomes necessary to study the natural radioactivity levels in soil to assess the dose for the population in order to know the health risks. The activity concentrations of (226)Ra, (232)Th and (40)K in the soil ranged from 5.7 ± 0.3 to 140 ± 7, from 9.0 ± 0.4 to 139 ± 7 and from 22 ± 1 to 319 ± 16 Bq kg(-1), respectively. The absorbed dose rate, annual effective dose rate, radium equivalent (Req), excess lifetime cancer risk, hazard indices (Hex and Hin) and annual gonadal dose equivalent, which resulted from the natural radionuclides in the soil were calculated.

Organic and conventional fertilisation procedures on the nitrate, antioxidants and pesticide content in parts of vegetables.

Different parts of plant foods are generally discarded by consumers such as peel, stalk and leaves, which could however possess a nutritional value. However, few studies have analysed the composition of these marginal foods. The phenolic compound, flavonoid, polyamine, nitrate and pesticide contents of parts of vegetables that are usually discarded--but which were cultivated according to conventional and non-conventional procedures--were analysed to provide suggestions on how to improve the consumption of these parts and to reduce the production of urban solid waste. Few, but significant, differences between the two manuring procedures were observed. Higher nitrate content and the presence of organochlorine pesticides were found in conventional cultivated papaya peel, lemon balm leaves, jack fruit pulp, and beet stalk and peel. Discarded parts of plant foods such as stalk, leaves and peels can be used as a source of antioxidant compounds, such as phenolic compounds.

Influence of calcium and silicon supplementation into Pleurotus ostreatus substrates on quality of fresh and canned mushrooms.

Supplements of gypsum (calcium source), pumice (silicon source) and pumice sulfate (silicon and calcium source) into substrates for oyster mushrooms (Pleurotus ostreatus) were searched for their effects on production as well as qualities of fresh and canned mushrooms. The addition of pumice up to 30% had no effect on total yield, size distribution and cap diameters. The supplementation of gypsum at 10% decreased the total yield; and although gypsum at 5% did not affect total yield, the treatment increased the proportion of large-sized caps. High content (>10%) of pumice sulfate resulted in the lower yield. Calcium and silicon contents in the fruit bodies were not influenced by supplementations. The centrifugal drip loss values and solid content of fresh mushrooms, and the percentage of weight gained and firmness of canned mushrooms, cultivated in substrates supplemented with gypsum, pumice and pumice sulfate were significantly (p≤0.05) higher than those of the control. Scanning electron micrographs revealed the more compacted hyphae of mushroom stalks supplemented with silicon and/or calcium after heat treatment, compared to the control. Supplementation of P. ostreatus substrates with 20% pumice was the most practical treatment because it showed no effect on yield and the most cost-effective.

How do we sell the hygiene message? With dollars, dong or excreta?

In North and Central Vietnam it is common among farmers to use excreta from the family double vault composting latrine (DVC) as fertilizer in the fields. The official Vietnamese health guidelines stipulate a six-month period of composting before applying excreta to two of their three annual crops. However, farmers in this region cannot afford to follow these guidelines and this paper presents the reasons why.In their efforts to ensure optimal hygienic conditions, by providing a guideline, the Vietnamese health authorities have not put sufficient attention to the 'excreta economy' in relation to farmers' livelihoods. The free fertilizer in the household DVC represents a value of approximately US$ 15.5 per year--or the equivalent of 15 percent of the annual household income for the poorest 20 percent of farmers. For this reason, the economic benefits derived from free fertilizer outweigh the hygiene message for most Vietnamese farmers. Even at national level the excreta economy has an impact. If Vietnam were to replace human excreta with imported fertilizer, it would involve an extra national expenditure of at least US$ 83 million a year.In order to convince Vietnamese farmers to adopt different fertilizing methods when reusing human excreta, it is necessary for the Vietnamese health authorities to change their hygiene message. They need to replace their current health sector-specific approach with a holistic one that takes the premises of farmers' livelihoods into account. If they do not the hygiene message will simply be lost.

Assessment and management of risks arising from exposure to cadmium in fertilisers. I.

A risk assessment protocol has been developed for use by individual EU Member States with appropriate selection of input data, to assess the risks to humans and the environment arising from exposure to cadmium in fertilisers. The protocol comprises of three modules: (1) the accumulation module, in which the net accumulation of cadmium in soil and soil solution, resulting from the application of fertiliser, is computed over time. The accumulation module allows for a range of inputs from different sources (atmospheric deposition, sludge addition, manure and fertiliser application) as well as for average and extreme rates of fertiliser application. A critical parameter is the solid/liquid partition coefficient, which in turn is a function of soil properties such as pH and is highly variable depending on the algorithm selected as being representative of national conditions. (2) The exposure module, in which the uptake of cadmium from soil into plants and the subsequent intake of cadmium by humans is computed, using exposure parameters characterising both average and extreme exposure scenarios. The protocol focuses on food types known to be sensitive to cadmium uptake (grain, cereals, potatoes, root vegetables and leafy vegetables). Environmental exposure is also characterised. (3) The risk characterisation module, in which Member States may estimate the incidence and severity of the adverse effects likely to occur due to actual or predicted exposure to cadmium. This is undertaken by modelling the Predicted Environmental Concentrations (PECs) in humans and the environment using the accumulation and exposure modules, and then comparing these values against the relevant Predicted No Effect Concentrations (PNECs). A range of environmental PNEC values are reported in the literature; the European Commission recommends that normally the lowest No Observed Adverse Effect Level (NOAEL) should be used in the risk characterisation. For humans, the current WHO Provisional Tolerable Weekly Intake (PTWI) is equivalent to a daily intake of 70 microg Cd day(-1). Particular risk groups can be characterised, namely of: children; smokers; women with low iron stores; consumers of food items with high cadmium content; and extreme consumers of staple food items. At present, with the data available, it is not possible to characterise risk groups in detail, either at EU level or at Member State level. However, most Member States appear to have an average intake of cadmium which is lower than the WHO's PTWI.

Assessment and management of risks arising from exposure to cadmium in fertilisers--II.

A preliminary, illustrative human health risk assessment of exposure to cadmium in phosphate fertilisers was performed using typical UK data and a protocol previously developed for application by individual Member States in the European Union. The risk assessment indicated that the for the most pessimistic population exposures characterised by both extreme (97th percentile) cereal and potato consumption and high susceptibility to cadmium uptake, the estimated dose was under the WHO Provisional Tolerable Weekly Intake (PTWI) for fertiliser cadmium concentrations ranging from 15 to 100 mg Cd/kg P2O5 applied over 100 years. However, the low margin of safety for high risk groups and the uncertainties inherent in the overall risk assessment suggested that a prudent risk management strategy would involve maintenance of low levels of cadmium in fertilisers and/or conditions that permitted low accumulation of cadmium in soils. On this basis, two main risk reduction measures were developed and assessed: (a) imposition of limits on cadmium concentration in fertilisers; and (b) imposition of charges on levels of cadmium in phosphate fertilisers. An assessment of the economic impact of these risk reduction measures indicated that, at all price elasticities, the most significant impact in terms of changes in demand and changes in consumer expenditure on phosphate fertilisers will be seen with cadmium charges where no thresholds are defined. The impact on the consumer (i.e. farmer) will be an increase in spending of approximately US $4000 per year, which is considered significant, accompanied by a decrease in demand above 20%. If a threshold is set at 60 mg Cd/kg P2O5, the impact is significantly reduced, but stays relatively high compared to the other options. The analysis also indicates that the use of low-cadmium rock is the low cost option. At a likely rock price increase of approximately 5% and assuming a likely price elasticity of -0.2, the yearly costs to farmers will be approximately US $82 which is considered a minimal impact. In the worst case scenario (elasticity of -0.6 and a 10% increase in rock prices), the increase in spending by farmers will be of 3.9% or US $221 which is also considered to represent a minimal impact. At similar price elasticities, the use of decadmation technologies is predicted to be more costly than the use of low-cadmium rock but this option can still be considered as having a minimal impact on the consumer (increase in expenditure of 1.9-13.3% or US $106-748).