Pre-Conception And First Trimester Exposure To Pesticides And Associations With Stillbirth.

Associations of pesticide exposures during pre-conception with stillbirth have not been well explored. We linked Arizona pesticide use records with birth certificates from 2006-2020 and estimated associations of living within 500meters of any pyrethroid, organophosphate (OP), or carbamate pesticide applications during a 90 day pre-conception window or the first trimester, with stillbirth. We considered a binary measure of exposure (any exposure), as well as log-pounds and log-acres applied within 500m, in a negative control exposure framework with log-binomial regression.

Towards quantifying atmospheric dispersion of pesticide spray drift in Yuma County Arizona.

While pesticide vapor and particles from agricultural spray drift have been reported to pose a risk to public health, limited baseline ambient measurements exist to warrant an accurate assessment of their impacts at community-to-county-wide scale. Here, we present an initial modeling investigation of the transport and deposition of applied pesticides in an agricultural county in Arizona (Yuma County), to provide initial estimates on the corresponding enhancements in ambient levels of these spray drifts downwind of application sites. With a 50 × 50 km domain, we use the dispersion model CALPUFF with meteorology from the Weather Research and Forecasting (WRF) to investigate the spatiotemporal distribution of pesticide abundance due to spray drift from a representative sample of nine application sites.

Unexpected slowdown of US pollutant emission reduction in the past decade.

Ground and satellite observations show that air pollution regulations in the United States (US) have resulted in substantial reductions in emissions and corresponding improvements in air quality over the last several decades. However, large uncertainties remain in evaluating how recent regulations affect different emission sectors and pollutant trends. Here we show a significant slowdown in decreasing US emissions of nitrogen oxides (NO ) and carbon monoxide (CO) for 2011-2015 using satellite and surface measurements.

Spatial and Temporal Variations in Characteristic Ratios of Elemental Carbon to Carbon Monoxide and Nitrogen Oxides across the United States.

A ratio-based method is used to characterize anthropogenic elemental carbon (EC) using in situ measurements and emissions of carbon monoxide (CO) and nitrogen oxides (NO). We use long-term records of ground-based measurements from the U.S.

Frequency and Character of Extreme Aerosol Events in the Southwestern United States: A Case Study Analysis in Arizona.

This study uses more than a decade's worth of data across Arizona to characterize the spatiotemporal distribution, frequency, and source of extreme aerosol events, defined as when the concentration of a species on a particular day exceeds that of the average plus two standard deviations for that given month. Depending on which of eight sites studied, between 5% and 7% of the total days exhibited an extreme aerosol event due to either extreme levels of PM, PM, and/or fine soil. Grand Canyon exhibited the most extreme event days (120, , 7% of its total days).

Decreasing Aerosol Loading in the North American Monsoon Region.

We examine the spatio-temporal variability of aerosol loading in the recent decade (2005-2014) over the North American Monsoon (NAM) region. Emerging patterns are characterized using aerosol optical depth (AOD) retrievals from the NASA Terra/Moderate Resolution Imaging Spectroradiometer (MODIS) instrument along with a suite of satellite retrievals of atmospheric and land-surface properties. We selected 20 aerosol hotspots and classified them into fire, anthropogenic, dust, and NAM alley clusters based on the dominant driver influencing aerosol variability.

Spatiotemporal Distribution of Airborne Particulate Metals and Metalloids in a Populated Arid Region.

A statistical analysis of data from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network of aerosol samplers has been used to study the spatial and temporal concentration trends in airborne particulate metals and metalloids for southern Arizona. The study region is a rapidly growing area in southwestern North America characterized by high fine soil concentrations (among the highest in the United States), anthropogenic emissions from an area within the fastest growing region in the United States, and a high density of active and abandoned mining sites. Crustal tracers in the region are most abundant in the summer (April - June) followed by fall (October - November) as a result of dry meteorological conditions which favor dust emissions from natural and anthropogenic activity.

Continental-scale partitioning of fire emissions during the 1997 to 2001 El Niño/La Niña period.

During the 1997 to 1998 El Niño, drought conditions triggered widespread increases in fire activity, releasing CH4 and CO2 to the atmosphere. We evaluated the contribution of fires from different continents to variability in these greenhouse gases from 1997 to 2001, using satellite-based estimates of fire activity, biogeochemical modeling, and an inverse analysis of atmospheric CO anomalies. During the 1997 to 1998 El Niño, the fire emissions anomaly was 2.