A new strategy for risk assessment of PM2.5-bound elements by considering the influence of wind regimes.

For regulatory purposes, air pollution has been reduced to management of air quality control regions (AQCR), by inventorying pollution sources and identifying the receptors significantly affected. However, beyond being source-dependent, particulate matter can be physically and chemically altered by factors and elements of climate during transport, as they act as local environmental constraints, indirectly modulating the adverse effects of particles on the environment and human health. This case study, at an industrial site in a Brazilian coastal city - Joinville, combines different methodologies to integrate atmospheric dynamics in a strategic risk assessment approach whereby the influence of different wind regimes on environmental and health risks of exposure to PM2.5-bound elements, are analysed. Although Joinville AQCR has been prone to stagnation/recirculation events, distinctly different horizontal wind circulation patterns indicate two airsheds within the region. The two sampling sites mirrored these two conditions and as a result we report different PM2.5 mass concentrations, chemical profiles, geo-accumulation, and ecological and human health risks. In addition, feedback mechanisms between the airsheds seem to aggravate the air quality and its effects even under good ventilation conditions. Recognizably, the risks associated with Co, Pb, Cu, Ni, Mn, and Zn loadings were extremely high for the environment as well as being the main contributors to elevated non-carcinogenic risks. Meanwhile, higher carcinogenic risks occurred during stagnation/recirculation conditions, with Cr as the major threat. These results highlight the importance of integrating local airshed characteristics into the risk assessment of PM2.5-bound elements since they can aggravate air pollution leading to different risks at a granular scale. This new approach to risk assessment can be employed in any city's longer-term development plan since it provides public authorities with a strategic perspective on incorporating environmental constraints into urban growth planning and development zoning regulations.

Impact of El Niño on the dynamics of American cutaneous leishmaniasis in a municipality in the western Amazon.

Vector-borne diseases are some of the leading public health problems in the tropics, and their association with climatic anomalies is well known. The current study aimed to evaluate the trend of American cutaneous leishmaniasis cases in the municipality of Manaus, Amazonas-Brazil, and its relationship with climatic extremes (ENSO). The study was carried out using a series of secondary data from notifications on the occurrence of several American cutaneous leishmaniasis cases in the municipality of Manaus between 1990 and 2017 obtained through the Sistema de Informação de Agravos de Notificação. Data regarding temperature, relative humidity, and precipitation for this municipality were derived from the Instituto Nacional de Meteorologia (INMET) and the National Oceanic and Atmospheric Administration (NOAA) websites. Coherence and wavelet phase analysis was conducted to measure the degree of relationship of the occurrence of the cases of cutaneous leishmaniasis and the El Niño-Southern Oscillation (ENSO). The results show that during La Niña events, an increase in American cutaneous leishmaniasis (ACL) cases is anticipated after the increase in rainfall from November, resulting in a more significant number of cases in January, February, and March. It was observed that in the municipality of Manaus, the dynamics of ACL cases are directly influenced by ENSO events that affect environmental variables such as precipitation, temperature, and humidity. Therefore, climatic variations consequently change the ACL incidence dynamics, leading to subsequent increases or decreases in the incidence of ACL cases in the area.

Impact of the biomass burning on methane variability during dry years in the Amazon measured from an aircraft and the AIRS sensor.

The present study examines the spatiotemporal variability and interrelations of the atmospheric methane (CH4), carbon monoxide (CO) and biomass burning (BB) outbreaks retrieved from satellite data over the Amazon region during the 2003-2012 period. In the climatological context, we found consistent seasonal cycles of BB outbreaks and CO in the Amazon, both variables showing a peak during the dry season. The dominant CO variability mode features the largest positive loadings in the southern Amazon, and describes the interannual CO variations related to BB outbreaks along the deforestation arc during the dry season. In line with CO variability and BB outbreaks, the results show strong correspondence with the spatiotemporal variability of CH4 in the southern Amazon during years of intense drought. Indeed, the areas with the largest positive CH4 anomalies in southern Amazon overlap the areas with high BB outbreaks and positive CO anomalies. The analyses also showed that high (low) BB outbreaks in the southern Amazon occur during dry (wet) years. In consequence, the interannual climate variability modulates the BB outbreaks in the southern Amazon, which in turn have considerable impacts on CO and CH4 interannual variability in the region. Therefore, the BB outbreaks might play a major role in modulating the CH4 and CO variations, at least in the southern Amazon. This study also provides a comparison between the estimate of satellite and aircraft measurements for the CH4 over the southern Amazon, which indicates relatively small differences from the aircraft measurements in the lower troposphere, with errors ranging from 0.18% to 1.76%.

Airborne observations reveal elevational gradient in tropical forest isoprene emissions.

Isoprene dominates global non-methane volatile organic compound emissions, and impacts tropospheric chemistry by influencing oxidants and aerosols. Isoprene emission rates vary over several orders of magnitude for different plants, and characterizing this immense biological chemodiversity is a challenge for estimating isoprene emission from tropical forests. Here we present the isoprene emission estimates from aircraft eddy covariance measurements over the Amazonian forest. We report isoprene emission rates that are three times higher than satellite top-down estimates and 35% higher than model predictions. The results reveal strong correlations between observed isoprene emission rates and terrain elevations, which are confirmed by similar correlations between satellite-derived isoprene emissions and terrain elevations. We propose that the elevational gradient in the Amazonian forest isoprene emission capacity is determined by plant species distributions and can substantially explain isoprene emission variability in tropical forests, and use a model to demonstrate the resulting impacts on regional air quality.