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Dust emissions from unpaved roads are one of the main pollutants affecting air quality around the world. As part of initial air quality studies in Tuxtla Gutiérrez (TGZ), Chiapas, Mexico, urban aeolian emission events from unpaved roads and simple meteorological inputs were measured in February 2014 at two different sites located within the city to characterize emissions for representative road conditions and to produce Industrial Source Complex (ISC3) model inputs. Emissions of particulate matter of aerodynamic diameter less than 10 µm (PM10) were determined for eight wind erosion events. PM10 concentrations were measured downwind from sites using a Minivol sampler during February and March 2014. Three high PM10 concentration scenarios, associated with unstable conditions generated by cold fronts (CF) were selected to simulate dust plume dispersion to identify impacted areas. Results show that unpaved roads represent a potential source of dust that affect air quality of urban regions; in this study generating emissions ≥ 1.92 x 10-3 g·m-2·s-1when winds ≥ 6 m·s-1 were present. Air pollution events that exceed the Mexico national standard for 24-h average PM10 concentration (≥75 µg·m-3) were observed, impacting different areas in the city, representing a risk to human health. This demonstrates the influence of CF over southern Mexico, generating high PM10 concentrations in urban regions. [ABSTRACT FROM AUTHOR]

Abstract: Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (OM>20%) in half or more of the upper 80cm. Forty two states have a total of 21 million ha of Histosols in the United States. These soils, when intensively cropped, are subject to wind erosion resulting in loss of crop productivity and degradation of soil, air, and water quality. Estimating wind erosion on Histosols has been determined by USDA–Natural Resources Conservation Service (NRCS) as a critical need for the Wind Erosion Prediction System (WEPS) model. WEPS has been developed to simulate wind erosion on agricultural land in the US, including soils with organic soil material surfaces. However, additional field measurements are needed to understand how soil properties vary among organic soils and to calibrate and validate estimates of wind erosion of organic soils using WEPS. Soil properties and sediment flux were measured in six soils with high organic contents located in Michigan and Florida, USA. Soil properties observed included organic matter content, particle density, dry mechanical stability, dry clod stability, wind erodible material, and geometric mean diameter of the surface aggregate distribution. A field portable wind tunnel was used to generate suspended sediment and dust from agricultural surfaces for soils ranging from 17% to 67% organic matter. The soils were tilled and rolled to provide a consolidated, friable surface. Dust emissions and saltation were measured using an isokinetic vertical slot sampler aspirated by a regulated suction source. Suspended dust was sampled using a Grimm optical particle size analyzer. Particle density of the saltation-sized material (>106μm) was inversely related to OM content and varied from 2.41gcm−3 for the soil with the lowest OM content to 1.61gcm−3 for the soil with highest OM content. Wind erodible material and the geometric mean diameter of the surface soil were inversely related to dry clod stability. The effect of soil properties on sediment flux varied among flux types. Saltation flux was adequately predicted with simple linear regression models. Dry mechanical stability was the best single soil property linearly related to saltation flux. Simple linear models with soil properties as independent variables were not well correlated with PM10 E values (mass flux). A second order polynomial equation with OM as the independent variable was found to be most highly correlated with PM10 E values. These results demonstrate that variations in sediment and dust emissions can be linked to soil properties using simple models based on one or more soil properties to estimate saltation mass flux and PM10 E values from organic and organic-rich soils. [Copyright &y& Elsevier]

• Wind erosion management is needed to address effects on health and agroecosystems. • Improved monitoring would enable effective wind erosion management. • Indicators for monitoring wind erosion and blowing dust are reviewed. • Best practices are identified for establishing benchmarks to support management. Wind erosion and blowing dust threaten food security, human health and ecosystem services across global drylands. Monitoring wind erosion is needed to inform management, with explicit monitoring objectives being critical for interpreting and translating monitoring information into management actions. Monitoring objectives should establish quantitative guidelines for determining the relationship of wind erosion indicators to management benchmarks that reflect tolerable erosion and dust production levels considering impacts to, for example, ecosystem processes, species, agricultural production systems and human well-being. Here we: 1) critically review indicators of wind erosion and blowing dust that are currently available to practitioners; and 2) describe approaches for establishing benchmarks to support wind erosion assessments and management. We find that while numerous indicators are available for monitoring wind erosion, only a subset have been used routinely and most monitoring efforts have focused on air quality impacts of dust. Indicators need to be related to the causal soil and vegetation controls in eroding areas to directly inform management. There is great potential to use regional standardized soil and vegetation monitoring datasets, remote sensing and models to provide new information on wind erosion across landscapes. We identify best practices for establishing benchmarks for these indicators based on experimental studies, mechanistic and empirical models, and distributions of indicator values obtained from monitoring data at historic or existing reference sites. The approaches to establishing benchmarks described here have enduring utility as monitoring technologies change and enable managers to evaluate co-benefits and potential trade-offs among ecosystem services as affected by wind erosion management. [ABSTRACT FROM AUTHOR]