Tractor rollover fatalities, analyzing accident scenario

INTRODUCTION

In many countries, traditional data sources for collecting injuries of workers covered by compulsory accident insurance have recently been integrated by new observatories whose results may differ. A comparative analysis of the Italian data collection systems related to fatal tractor accidents in agriculture was performed focusing on tractor rollover fatalities with the aim of analyzing the accident scenario.

METHOD

Data from the Operational Archives of the Italian Workers Compensation Authority (INAIL), which collects injuries of workers covered by compulsory accident insurance and those of the National Surveillance System (INAIL_ASL), which provides narrative text reports of work-related fatal accidents have been analyzed and compared to the information collected by the INAIL Observatory. The INAL Observatory was recently set up to complement the collection of fatal accidents involving agricultural machinery. Italian data were then compared to data available at an international level. Fatal tractor accidents vary considerably with respect to fatal accidents in agriculture, being 10.6 and 43.7% for the Operational Archives and Surveillance System, respectively. National Surveillance System records, implemented with narrative texts allowed the accident scenario to be defined.

RESULTS

71.7% of fatal tractor-related accidents refer to non-ROPS equipped vehicles and of these, 26.5% involved machines originally mounted with a ROPS that had been removed or was inoperative in the folded-down position during the rollover event. Just one fatal event from a collapsed ROPS on the overturned tractor was recorded. It is interesting that 16.6% of fatal accidents involved a clear environmental factor.

PRACTICAL APPLICATION

A campaign to train tractor drivers on the correct use of the combination ROPS and seatbelt can contribute to decreasing rollover events with fatal outcomes. Contemporarily a strict requirement to install ROPS and a seatbelt on tractors, combined to an official inspection at the farm level, can increase the chance of survival in a rollover accident.

Global trends in nitrate leaching research in the 1960-2017 period

Nitrate leaching is the process whereby the nitrate (NO₃^-) anion moves downwards in the soil profile with soil water. Nitrate leaching is commonly associated with chemical nitrogen (N) fertilizers used in agriculture. Nitrate leaching from different sources and contamination of surface and groundwater is a global phenomenon that has prompted social and political pressure to reduce nitrate leaching and contamination of water bodies. This bibliometric study analyzed global trends in nitrate leaching research. The results showed a rising interest in the last decades in this topic; given the growth tendency over the last years, it was envisaged that the importance on nitrate leaching research will continue increasing in the future. Knowledge on nitrate leaching was mostly disseminated through scientific publications (90% of total documents recovered), both as journal articles and reviews, classified in the Scopus database in the Agricultural, Biological and Environmental Sciences areas. Most publications dealt with soil nitrogen losses from agroecosystems and farmlands and the associated impact on the environment; they were published in journals with a focus on the influence of anthropogenic and soil-crop-animal systems in the environment, and on how such changes in the environment impact agroecosystems. Most documents published on nitrate leaching were indisputably from the United States, followed by China, the United Kingdom and Germany. An analysis of the main keywords showed an overall dominance of the soil nitrogen cycle, fertilizer use in agriculture and water quality aspects. The evolution of main crop species involved in nitrate leaching research showed a rising relevance of research conducted with maize, wheat and grasses from 1990 onwards. The most productive institutions in terms of number of documents dealing with nitrate leaching research, h-index and total citations, were located in the United States, China and the Netherlands. The United States Department of Agriculture stood out, followed by the Chinese Academy of Sciences and Wageningen University and Research. There were clusters of institutions with intercontinental interaction, on nitrate leaching research, between institutions from Europe, Asia and South and North America. Overall, this study has highlighted, from a bibliometric perspective, the rising concern on nitrate leaching. Progress in this field has been made particularly on the impact of the soil-plant-animal system on the environment and agroecosystems, and on fundamental and applied aspects of plant-soil interactions with an emphasis in cropping systems.

The impact and relevance of tobacco control research in low-and middle-income countries globally and to the US

International and cross-cultural research is critical for understanding multilevel influences on health, health behaviors, and disease. A particularly relevant area of need for such research is tobacco control. The tobacco epidemic is one of the biggest public health threats globally, killing over 7 million people a year. Research critical to addressing this public health problem has leveraged variability in tobacco use, history, product market, and policies across different countries, settings, and populations, particularly in low- and middle-income countries (LMICs) where the tobacco burden is increasing. These efforts are needed in order to advance the science and inform practice and policy in various settings, including the US. Several funding agencies provide support for international research focused on tobacco control in LMICs because of the importance and implications of such research. This paper provides some concrete examples of how such research has advanced our knowledge-base and informed practice and policy globally, particularly in high-income countries including the US. Some prominent themes emphasized in this manuscript include: the development of knowledge regarding the diverse tobacco products on the market; better understanding of tobacco use and its impact among different populations; generating knowledge about the impacts including unintended consequences of tobacco control policy interventions; and better understanding tobacco industry strategies and informing advocacy efforts. In summary, international tobacco control research, particularly in LMICs, is critical in effectively and efficiently building the evidence base to advance tobacco control research, policy, and practice globally, including the US, with the ultimate goal of curbing the tobacco epidemic.

Migrant Farmworkers' Exposure to Pesticides in Sonora, Mexico

Expanding agribusiness in Sonora, a state in Northern Mexico, has increased the demand for temporary migrant agricultural workers. Sonora is one of the top states in Mexico for pesticide utilization. We conducted an exploratory study to evaluate exposure to organophosphate (OP) and pyrethroid pesticides among migrant farmworkers. A sample of 20 migrant farmworkers was recruited from a large commercial grape farm during the harvest season. We administered a questionnaire on work activities, exposure characteristics, and socio-demographics. We collected urine samples to quantify pesticide metabolite concentrations. Most participants were originally from the state of Chiapas, Mexico, none had completed high school, and about half spoke an indigenous language as well as Spanish. The majority of participants had detectable concentrations of pyrethroid and organophosphate biomarkers. Geometric mean creatinine-adjusted concentrations for 3-phenoxybenzoic acid (1.83 µg/g), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (0.88 µg/g), 4-fluoro-3-phenoxybenzoic acid (0.94 µg/g), 3,5,6-trichloro-2-pyridinol (3.56 µg/g), and para-nitrophenol (0.63 µg/g) were significantly higher than in the general United States' population and Mexican Americans. Our results also suggest that migrant farmworkers in this region are exposed to pesticides at higher levels than other farmworkers' studies. Farmworkers' age, language, training on personal protective equipment, time at the farm, and season, were significant exposure determinants.

Modeling Water and Nutrient Movement in Sandy Soils Using HYDRUS-2D

Models help to describe and predict complex processes and scenarios that are difficult to understand or measure in environmental management systems. Thus, model simulations were performed (i) to calibrate HYDRUS-2D for water and solute movement as a possible decision support system for Candler and Immokalee fine sand using data from microsprinkler and drip irrigation methods, (ii) to validate the performance of HYDRUS-2D using field data of microsprinkler and drip irrigation methods, and (iii) to investigate Br, NO, and water movement using annual or seasonal weather data and variable fertigation scenarios. The model showed reasonably good agreement between measured and simulated values for soil water content ( = 0.87-1.00), Br ( = 0.63-0.96), NO-N ( = 0.66-0.98), P ( = 0.25-0.78), and K ( = 0.44-0.99) movement. The model could be successfully used for scheduling irrigation and predicting nutrient leaching for both microsprinkler and drip irrigation systems on Florida's sandy soils.

Association between exposure to pesticides and disorder on hematological parameters and kidney function in male agricultural workers

Pesticides occupy a critical position among many chemicals to which man can be exposed; their diffusion into the environment causes killing and damaging of some forms of life. The lack of highly selective pesticide action represents risk both for man and other desirable forms of life present in the environment. The present study was designed to evaluate the relation between exposure to pesticides and disorder on hematological parameters and kidney function of male agricultural workers with the mean age 37.11 ± 9.3. Another 100 unexposed men matched for age, and socioeconomic status were recruited as a control to compare the levels of hemoglobin, hematocrit, red blood cells (RBCs), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and urea and creatinine concentration. The results indicate that there was no significant difference in hemoglobin concentration and hematocrit value among exposed group as compared to control group. However, there was a significant decrease (P < 0.05) in the RBCs count and a highly significant increase (P < 0.01) in MCV among exposed group. There was no significant difference in MCH and MCHC among exposed group. There was a significant increase (P < 0.05) in urea (39.4 ± 22 mg/dl) among exposed group as compared to control (35.7 ± 26.3 mg/dl). Also, there was a highly significant increase (P < 0.01) in creatinine among exposed group (0.953 ± 0.3 mg/dl) as compared to control (0.8 ± 0.2 mg/dl). In conclusion, exposure to pesticides produces a variety of hematological parameter disorders as well as kidney malfunction in human.

A simple slash-and-char system to mitigate climate change and environmental pollution

Agriculture-based climate change mitigation may occur through enhancing the carbon sink or through reducing greenhouse gases (GHGs) emissions from agricultural residue treatment, as open burning of agricultural residues produces millions of tons of GHGs and air pollutants annually worldwide. Charring slashed biomass, termed as slash-and-char, has been considered as a promising alternative to open burning in dealing with agricultural residues such as rice straw. Previous studies, however, focused on relatively sophisticated slash-and-char systems, which could not be practiced easily by smallholder farmers in developing countries. Here we introduce a simple slash-and-char system to mitigate the environmental problems associated with open burning of rice straw. This system could convert 30.7% of the initial carbon in rice straw into biochar, much higher than that retained in the ash generated by open burning (3.95%). It could also cut GHGs, particulate matters and polycyclic aromatic hydrocarbons (PAHs) emissions by 26.9%, 99.0% and 99.4%, respectively. If open burning of rice straw was replaced by the slash-and-char, the annual emissions of GHGs, particulate matters and PAHs in China would decrease by at least 15.4 Tg, 1.51 Tg and 1.27 Gg, correspondingly. This decrease is nearly twice the size of China's estimated forest C sink (8.81 Tg).

Evaluation of pelvic inflammatory disease potential in cholinesterase inhibitor pesticide-exposed females

Cholinesterase inhibitor pesticides, mainly organophosphates and carbamates, are commonly used in Egypt. Chronic exposure of males and females working in agriculture is expected. The study aimed to relate exposure to cholinesterase inhibitor pesticides to the development of pelvic inflammatory disease (PID). This is a case-control study that was conducted among 84 females. Seventy patients complained of pelvic inflammatory disease visited the outpatient Gynecology and Obstetrics Clinic. Fourteen females were not suffering from PID and were chosen as a control group. Red blood cells' cholinesterase activity was measured in blood. Cervical swaps were collected, and cultures were submitted for microbiological examination. The results showed that cholinesterase activities were significantly depressed in exposed females (6.36 ± 0.8 μmoles/min/ml red cells) when compared to non-exposed (7.5 ± 1.2 μmoles/min/ml red cells), and both were significantly depressed when compared with healthy females (9.17 ± 0.7 μmoles/min/ml red cells). The correlation coefficient (r) between previous exposure and the laboratory confirmed cervical infection was 0.31, with a P value of 0.009. The study concluded that exposure to cholinesterase inhibitor pesticides could increase the occurrence of pelvic inflammatory disease.

Stream Nitrogen, Phosphorus, and Sediment Concentrations Show Contrasting Long-term Trends Associated with Agricultural Change

Stream water quality can be greatly influenced by changes in agricultural practices, but studies of long-term dynamics are scarce. Here we describe trends over 21 yr (1994-2014) in nutrients and suspended sediments in three streams in a Midwestern US agricultural watershed. During this time, the watershed experienced substantial changes in agricultural practices, most importantly a pronounced shift from conventional to conservation tillage. In the 1990s and early 2000s, NH, soluble reactive P, and suspended sediment concentrations (standardized for discharge and season) each declined significantly (>4-12% per year) in at least two of the three streams ( < 0.01), whereas NO changed relatively little. However, since the early 2000s, declines in NH and sediment concentrations have slowed, soluble reactive P concentrations have not declined and may actually have increased, and NO concentrations have declined sharply. The more recent lack of decline in soluble reactive P coincides with a plateau in the prevalence of conservation tillage and may be because of increased soil P stratification due to long-term reduced tillage. The more recent decline in NO may be due to improved efficiency of N fertilizer use, increased soil denitrification, and/or declines in atmospheric N deposition. Our study shows that stream concentrations of N, P, and sediment can respond in contrasting ways to changes in agriculture, and that temporal trends can moderate, accelerate, or reverse over decadal timescales. Management strategies must consider contrasting temporal responses of water quality indicators and may need to be adaptively adjusted at scales of years to decades.

Agricultural environmental total factor productivity in China under technological heterogeneity: characteristics and determinants

With limited resources, growing environment constraints and downward pressure on the economy, increasing agricultural environmental total factor productivity (AETFP) and its contribution to agricultural growth is significant for transforming agricultural development to make it more resource efficient and environment-friendly. This paper considered technological heterogeneity in different regions of China and measured AETFP in 30 provinces from 1997 to 2015 using the Metafrontier Malmquist-Luenberger (MML) productivity index. Multi-dimensional analysis was made on temporal and spatial characteristics, evolution patterns, and influencing factors of AETFP in China. The results showed that: (1) AETFP increased in the Ninth, Tenth, Eleventh, and Twelfth Five-Year Plan periods, with average annual growth rates of 0.76%, 0.88%, 1.17%, and 0.87%, respectively. (2) The average annual growth rate of AETFP in the eastern, central, and western regions decreased successively. The eastern region generally had played a leading role. The central region had a catch-up effect on environmental production technologies from the eastern region, while the western region lacked the catch-up effect. (3) The dynamic evolution of AETFP had prominent features. For the whole nation, the kernel density curve of AETFP continuously moved to the right. The main peak value continuously decreased and the width of the main peak continuously increased. The internal differences of AETFP in the eastern and western regions exhibited an increasing trend, while the internal differences of AETFP in the central region showed little change. (4) There was an inverted U-shaped relationship between agricultural economic growth and AETFP. Both the disaster rate and planting structure had a negative impact on AETFP with varying degrees of significance. Income gaps between urban and rural areas can partially offset the role of urbanization in promoting the growth of AETFP. The greater the income differences between urban and rural areas, the weaker the role of urbanization in promoting the growth of AETFP. These findings can help the government determine policies to change the agricultural development mode and formulate effective measures to improve AETFP.

Global distribution data for cattle, buffaloes, horses, sheep, goats, pigs, chickens and ducks in 2010

Global data sets on the geographic distribution of livestock are essential for diverse applications in agricultural socio-economics, food security, environmental impact assessment and epidemiology. We present a new version of the Gridded Livestock of the World (GLW 3) database, reflecting the most recently compiled and harmonized subnational livestock distribution data for 2010. GLW 3 provides global population densities of cattle, buffaloes, horses, sheep, goats, pigs, chickens and ducks in each land pixel at a spatial resolution of 0.083333 decimal degrees (approximately 10 km at the equator). They are accompanied by detailed metadata on the year, spatial resolution and source of the input census data. Two versions of each species distribution are produced. In the first version, livestock numbers are disaggregated within census polygons according to weights established by statistical models using high resolution spatial covariates (dasymetric weighting). In the second version, animal numbers are distributed homogeneously with equal densities within their census polygons (areal weighting) to provide spatial data layers free of any assumptions linking them to other spatial variables.

When too much isn't enough: Does current food production meet global nutritional needs?

Sustainably feeding the next generation is often described as one of the most pressing “grand challenges” facing the 21^st century. Generally, scholars propose addressing this problem by increasing agricultural production, investing in technology to boost yields, changing diets, or reducing food waste. In this paper, we explore whether global food production is nutritionally balanced by comparing the diet that nutritionists recommend versus global agricultural production statistics. Results show that the global agricultural system currently overproduces grains, fats, and sugars while production of fruits and vegetables and protein is not sufficient to meet the nutritional needs of the current population. Correcting this imbalance could reduce the amount of arable land used by agriculture by 51 million ha globally but would increase total land used for agriculture by 407 million ha and increase greenhouse gas emissions. For a growing population, our calculations suggest that the only way to eat a nutritionally balanced diet, save land and reduce greenhouse gas emissions is to consume and produce more fruits and vegetables as well as transition to diets higher in plant-based protein. Such a move will help protect habitats and help meet the Sustainable Development Goals.

Climate Change Adaptation through the Water-Energy-Food Nexus in Southern Africa

Climate change is a complex and cross-cutting problem that needs an integrated and transformative systems approach to respond to the challenge. Current sectoral approaches to climate change adaptation initiatives often create imbalances and retard sustainable development. Regional and international literature on climate change adaptation opportunities and challenges applicable to southern Africa from a water-energy-food (WEF) nexus perspective was reviewed. Specifically, this review highlights climate change impacts on water, energy, and food resources in southern Africa, while exploring mitigation and adaptation opportunities. The review further recommends strategies to develop cross-sectoral sustainable measures aimed at building resilient communities. Regional WEF nexus related institutions and legal frameworks were also reviewed to relate the WEF nexus to policy. Southern Africa is witnessing an increased frequency and intensity in climate change-associated extreme weather events, causing water, food, and energy insecurity. A projected reduction of 20% in annual rainfall by 2080 in southern Africa will only increase the regional socio-economic challenges. This is exacerbating regional resource scarcities and vulnerabilities. It will also have direct and indirect impacts on nutrition, human well-being, and health. Reduced agricultural production, lack of access to clean water, sanitation, and clean, sustainable energy are the major areas of concern. The region is already experiencing an upsurge of vector borne diseases (malaria and dengue fever), and water and food-borne diseases (cholera and diarrhoea). What is clear is that climate change impacts are cross-sectoral and multidimensional, and therefore require cross-sectoral mitigation and adaptation approaches. In this regard, a well-coordinated and integrated WEF nexus approach offers opportunities to build resilient systems, harmonise interventions, and mitigate trade-offs and hence improve sustainability. This would be achieved through greater resource mobilisation and coordination, policy convergence across sectors, and targeting nexus points in the landscape. The WEF nexus approach has potential to increase the resilience of marginalised communities in southern Africa by contributing towards attaining the Sustainable Development Goals (SDGs 1, 2, 3, 6, 7, and 13).

Closing the global ozone yield gap: Quantification and cobenefits for multistress tolerance

Increasing both crop productivity and the tolerance of crops to abiotic and biotic stresses is a major challenge for global food security in our rapidly changing climate. For the first time, we show how the spatial variation and severity of tropospheric ozone effects on yield compare with effects of other stresses on a global scale, and discuss mitigating actions against the negative effects of ozone. We show that the sensitivity to ozone declines in the order soybean > wheat > maize > rice, with genotypic variation in response being most pronounced for soybean and rice. Based on stomatal uptake, we estimate that ozone (mean of 2010-2012) reduces global yield annually by 12.4%, 7.1%, 4.4% and 6.1% for soybean, wheat, rice and maize, respectively (the "ozone yield gaps"), adding up to 227 Tg of lost yield. Our modelling shows that the highest ozone-induced production losses for soybean are in North and South America whilst for wheat they are in India and China, for rice in parts of India, Bangladesh, China and Indonesia, and for maize in China and the United States. Crucially, we also show that the same areas are often also at risk of high losses from pests and diseases, heat stress and to a lesser extent aridity and nutrient stress. In a solution-focussed analysis of these results, we provide a crop ideotype with tolerance of multiple stresses (including ozone) and describe how ozone effects could be included in crop breeding programmes. We also discuss altered crop management approaches that could be applied to reduce ozone impacts in the shorter term. Given the severity of ozone effects on staple food crops in areas of the world that are also challenged by other stresses, we recommend increased attention to the benefits that could be gained from addressing the ozone yield gap.

How Should Physicians Help Patients Who Are Ill Because They Work in Agriculture?

Occupational health issues are not just common for farmworkers; they are practically unavoidable. Farmworkers who seek treatment for work-related injury or illness are often unable to meaningfully reduce their exposure to risk factors without further jeopardizing their already fragile well-being and tenuous livelihoods. This case commentary addresses why and how physicians presented with patients who are ill because they work in agriculture should adjust their clinical practices to better meet the unique challenges faced by this patient population. In recognition of physicians' ethical duty to participate in activities to protect and promote the health of the public, this commentary also recommends specific actions that medical professionals can take to support systemic change that would improve farmworker health and well-being.

Uncertainties of potentials and recent changes in global yields of major crops resulting from census- and satellite-based yield datasets at multiple resolutions

Global agriculture is under pressure to meet increasing demand for food and agricultural products. There are several global assessments of crop yields, but we know little about the uncertainties of their key findings, as the assessments are driven by the single best yield dataset available when each assessment was conducted. Recently, two different spatially explicit, global, historical yield datasets, one based on agricultural census and the other largely based on satellite remote sensing, became available. Using these datasets, we compare the similarities and differences in global yield gaps, trend patterns, growth rates and changes in year-to-year variability. We analyzed maize, rice, wheat and soybean for the period of 1981 to 2008 at four resolutions (0.083°, 0.5°, 1.0° and 2.0°). Although estimates varied by dataset and resolution, the global mean annual growth rates of 1.7-1.8%, 1.5-1.7%, 1.1-1.3% and 1.4-1.6% for maize, rice, wheat and soybean, respectively, are not on track to double crop production by 2050. Potential production increases that can be attributed to closing yield gaps estimated from the satellite-based dataset are almost twice those estimated from the census-based dataset. Detected yield variability changes in rice and wheat are sensitive to the choice of dataset and resolution, but they are relatively robust for maize and soybean. Estimates of yield gaps and variability changes are more uncertain than those of yield trend patterns and growth rates. These tendencies are consistent across crops. Efforts to reduce uncertainties are required to gain a better understanding of historical change and crop production potential to better inform agricultural policies and investments.

Coupling and decoupling effects of agricultural carbon emissions in China and their driving factors

The relationship between agricultural carbon emissions and agricultural economic growth has attracted a significant research attention. A key issue to address in the development of agriculture is the reduction of agricultural carbon emissions while maintaining agricultural economic growth. This study investigated the interactions between agricultural carbon emissions and agricultural economic growth from multiple perspectives based on agricultural carbon emission data from 30 provinces in China measured from 1997 to 2015. Using this dataset, the coupling and decoupling effects of agricultural carbon emissions and the underlying driving factors were explored using a coupling development degree model, the Tapio decoupling assessment model, and a logarithmic mean Divisia index (LMDI) decomposition model. The results were as follows: (1) at the regional scale, the degree of coupling development between agricultural carbon emissions and agricultural economic growth is high in the central region of China and low in the western region. At the provincial scale, the coupling effects of agricultural carbon emissions exhibited four levels: minimal, low, moderate, and high coupling. (2) With the exceptions of Beijing, Zhejiang, Fujian, Guangdong, Inner Mongolia, and Shanghai, the relationships between agricultural carbon emissions and agricultural economic growth in the other 24 provinces were in a weak decoupling state. (3) The effects of agricultural development scale and agricultural technical progress were the major driving factors associated with increases and decreases in agricultural carbon emissions, respectively.

The Impacts of Land Use Patterns on Water Quality in a Trans-Boundary River Basin in Northeast China Based on Eco-Functional Regionalization

The relationships between land use patterns and water quality in trans-boundary watersheds remain elusive due to the heterogeneous natural environment. We assess the impact of land use patterns on water quality at different eco-functional regions in the Songhua River basin during two hydrological seasons in 2016. The partial least square regression indicated that agricultural activities associated with most water quality pollutants in the region with a relative higher runoff depth and lower altitude. Intensive grazing had negative impacts on water quality in plain areas with low runoff depth. Forest was related negatively with degraded water quality in mountainous high flow region. Patch density and edge density had major impacts on water quality contaminants especially in mountainous high flow region; Contagion was related with non-point source pollutants in mountainous normal flow region; landscape shape index was an effective indicator for anions in some eco-regions in high flow season; Shannon’s diversity index contributed to degraded water quality in each eco-region, indicating the variation of landscape heterogeneity influenced water quality regardless of natural environment. The results provide a regional based approach of identifying the impact of land use patterns on water quality in order to improve water pollution control and land use management.

Agricultural diversification as an important strategy for achieving food security in Africa

Farmers in Africa have long adapted to climatic and other risks by diversifying their farming activities. Using a multi-scale approach, we explore the relationship between farming diversity and food security and the diversification potential of African agriculture and its limits on the household and continental scale. On the household scale, we use agricultural surveys from more than 28,000 households located in 18 African countries. In a next step, we use the relationship between rainfall, rainfall variability, and farming diversity to determine the available diversification options for farmers on the continental scale. On the household scale, we show that households with greater farming diversity are more successful in meeting their consumption needs, but only up to a certain level of diversity per ha cropland and more often if food can be purchased from off-farm income or income from farm sales. More diverse farming systems can contribute to household food security; however, the relationship is influenced by other factors, for example, the market orientation of a household, livestock ownership, nonagricultural employment opportunities, and available land resources. On the continental scale, the greatest opportunities for diversification of food crops, cash crops, and livestock are located in areas with 500-1,000 mm annual rainfall and 17%-22% rainfall variability. Forty-three percent of the African cropland lacks these opportunities at present which may hamper the ability of agricultural systems to respond to climate change. While sustainable intensification practices that increase yields have received most attention to date, our study suggests that a shift in the research and policy paradigm toward agricultural diversification options may be necessary.

Global land change from 1982 to 2016

Land change is a cause and consequence of global environmental change1,2. Changes in land use and land cover considerably alter the Earth's energy balance and biogeochemical cycles, which contributes to climate change and-in turn-affects land surface properties and the provision of ecosystem services1-4. However, quantification of global land change is lacking. Here we analyse 35 years' worth of satellite data and provide a comprehensive record of global land-change dynamics during the period 1982-2016. We show that-contrary to the prevailing view that forest area has declined globally5-tree cover has increased by 2.24 million km2 (+7.1% relative to the 1982 level). This overall net gain is the result of a net loss in the tropics being outweighed by a net gain in the extratropics. Global bare ground cover has decreased by 1.16 million km2 (-3.1%), most notably in agricultural regions in Asia. Of all land changes, 60% are associated with direct human activities and 40% with indirect drivers such as climate change. Land-use change exhibits regional dominance, including tropical deforestation and agricultural expansion, temperate reforestation or afforestation, cropland intensification and urbanization. Consistently across all climate domains, montane systems have gained tree cover and many arid and semi-arid ecosystems have lost vegetation cover. The mapped land changes and the driver attributions reflect a human-dominated Earth system. The dataset we developed may be used to improve the modelling of land-use changes, biogeochemical cycles and vegetation-climate interactions to advance our understanding of global environmental change1-4,6.

Potential dermal exposure to operators applying pesticide on greenhouse crops using low-cost equipment

During pesticide application, operators are exposed to chemical products. Dermal exposure has been reported as the principal means of exposure for growers. In the present work, potential dermal exposure (PDE) has been assessed when using new low-cost equipment (a knapsack with a vertical spray boom) and compared to a hand-held spray lance, which is the equipment most widely used by growers in greenhouses. Two sprayers were used, a hand-held spray lance with four twin flat-fan nozzles and a knapsack fitted out with a vertical spray boom containing 3 pairs of twin flat-fan nozzles. Three applications were carried out and compared, one with the spray lance walking backwards (the reference application), and two with the spray boom - the first stopping at the turns and the second with no stopping. The patch method (19 position on the body) and tartrazine (the tracer) were used to assess de PDE. Each application tested was replicated three times. The results show that the knapsack with the vertical boom should not be used walking continuously along the greenhouse rows because the total PDE (1637.12mL 1000L^-1) is greater than in the rest of the configurations tested. If the operator stops at the turns for a few seconds, allowing the previously sprayed droplet cloud to dissipate, the level of exposure decreases significantly (324.63mL 1000L^-1), providing similar results to the reference application with the spray lance walking backwards (292.25mL 1000L^-1).

Effects of land use on the concentration and emission of nitrous oxide in nitrogen-enriched rivers

Nitrous oxide (N₂O) is a potent greenhouse gas that contributes to climate change and stratospheric ozone destruction. Nitrogen-enriched rivers are significant sources of atmospheric N₂O. This study conducted a one-year field campaign in seven N-enriched rivers draining urban, rural, and agricultural land to determine the link between the production, concentrations, and emissions of N₂O and land use. Estimated N₂O fluxes varied between 1.30 and 1164.38 μg N₂O-N m^-2 h^-1 with a mean value of 154.90 μg N₂O-N m^-2 h^-1, indicating that rivers were the net sources of atmospheric N₂O. Concentrations of N₂O ranged between 0.23 and 29.21 μg N₂O-N L^-1 with an overall mean value of 3.81 μg N₂O-N L^-1. Concentrations of ammonium and nitrate in urban and rural rivers were high in the cold season. The concentrations were also high in agricultural rivers in the wet season. N₂O concentrations and emissions in rural and urban rivers followed a similar pattern to ammonium and a similar pattern to nitrate in agricultural rivers. A strong link between the concentrations and emissions of N₂O and land use was observed. N₂O concentrations in and emissions from the rivers draining the urban and rural areas were significantly higher than the rivers draining the agricultural areas (P < 0.01). Stepwise regression analysis indicated that dissolved N₂O were primarily influenced by NH₄⁺ in agricultural rivers and by NO₃^- in rural rivers; while dissolved N₂O in urban rivers was primarily predicted by temperature and reflected the integrated impact of sewage input and river hydrology. Nitrate-N and NO^3--O isotope data and linear regression of N₂O and river water variables strongly indicated that dissolved N₂O was mainly derived from nitrification in agricultural rivers and denitrification in rural and urban rivers.

Groundwater nutrient inputs into an urbanized tropical estuary system in Indonesia

Groundwater discharge is known to transport nutrients into estuaries at several locations around the world. However, few studies report groundwater-associated nutrient fluxes from tropical developing regions such as Southeast Asia, even though this area shows the strongest human modifications in the coastal zone worldwide. We investigated groundwater nutrient flux into two streams and estuaries (Awur and Sekumbu Bay) in the urban area of Jepara, Indonesia, and its relation with the land usage surrounding the estuaries. We found that average concentrations of NO₃, NH₄, and PO₄ in Jepara's aquifer reached 145μM, 68μM, and 14μM, respectively, and our results indicate that these were mainly originated from untreated sewage, agriculture, and manure input. Approximately 2200tonNyear^-1 and 380tonPyear^-1 were removed in the soil and aquifer before the nutrients were discharged into the river. The total groundwater discharge into the river and estuary was estimated to 461×10³m³d^-1, or up to 42% of the river discharge. Discharge of groundwater-associated NO₃ (72×10³mold^-1), NH₄ (34×10³mold^-1), PO₄ (5×10³mold^-1), and additional surface runoff may contribute to eutrophication and a decrease of nearshore surface water quality. Nutrient concentrations in groundwater, river, and coastal seawater in the Jepara region are similar to those found in major urban areas in Southeast Asia, e.g. Manila and Bangkok, even though Jepara has smaller size and population. Thus, our results indicate that medium populated cities with highly modified regional land use can contribute a significant amount of nutrient discharge in the coastal area and should be included in global assessments of nutrient budget calculation.

Object-based land-use/land-cover change detection using Landsat imagery: a case study of Ardabil, Namin, and Nir counties in northwest Iran

In this study, land-use/land-cover (LULC) change in the Ardabil, Namin, and Nir counties, in the Ardabil province in the northwest of Iran, was detected using an object-based method. Landsat images including Thematic Mapper (TM), Landsat Enhanced Thematic Mapper Plus (ETM⁺), and Operational Land Imager (OLI) were used. Preprocessing methods, including geometric and radiometric correction, and topographic normalization were performed. Image processing was conducted according to object-based image analysis using the nearest neighbor algorithm. An accuracy assessment was conducted using overall accuracy and Kappa statistics. Results show that maps obtained from images for 1987, 2002, and 2013 had an overall accuracy of 91.76, 91.06, and 93.00%, and a Kappa coefficient of 0.90, 0.83, and 0.91, respectively. Change detection between 1987 and 2013 shows that most of the rangelands (97,156.6 ha) have been converted to dry farming; moreover, residential and other urban land uses have also increased. The largest change in land use has occurred for irrigated farming, rangelands, and dry farming, of which approximately 3539.8, 3086.9, and 2271.9 ha, respectively, have given way to urban land use for each of the studied years.

Serum concentrations of organochlorine compounds and predictors of exposure in children living in agricultural communities from South-Eastern Spain

BACKGROUND

Information on exposure levels to organochlorine compounds (OCs) in child population is limited, despite their greater vulnerability to the adverse health effects of these chemicals.

OBJECTIVE

To determine serum concentrations of 10 OCs (including organochlorine pesticides and polychlorinated biphenyls -PCBs-) in children living in agricultural communities from Almería (South-Eastern Spain), and to identify the main predictors of exposure related to socio-economic characteristics, diet and lifestyle.

METHODS

A cross-sectional study was conducted on 133 children aged 6-11 years selected from public schools of the study area. OCs compounds were determined in serum samples by GC/ECD. Anthropometric measures were obtained during sample collection. Information on sociodemographic characteristics, parental occupation, residential history, lifestyle and frequency of food consumption, among other relevant factors, was obtained by questionnaires administered to the mothers.

RESULTS

Geometric means of serum concentrations (ng/ml) were 0.11 for β-hexachloro-cyclohexane (β-HCH), 0.09 for endosulfan, 0.20 for endosulfan-ether, 0.51 for hexachorobenzene (HCB), 0.08 for mirex, 0.06 for oxychlordane, 0.36 for p,p'-DDE, 0.20 for PCB 138, 0.36 for PCB 153, and 0.45 for PCB 180. Percentage of samples above the limit of detection (0.05 ppb) ranged from 32 (β-HCH) to 100 (HCB). A high variability in OC levels depending on the compound was observed between our results and others found in similar studies carried out in children. Variables related to fish consumption were found to be the major dietary determinant of PCB 138, p,p´-DDE, endosulfan-α, β-HCH, mirex and oxychlordane levels.

CONCLUSIONS

Children participating in this study showed detectable levels of many OC, despite these compounds are no longer used. Their presence in children serum can be explained by their high lipophilicity and environmental persistence, leading to contamination of fatty food. In this line, fish consumption seemed to be the most relevant determinant of OC levels found in our study.