Increased burned area in the Pantanal over the past two decades

Indirect Methods to Determine the Risk of Damage to the Health of Firefighters and Children Due to Exposure to Smoke Emission from Burning Wood/Coal in a Controlled Environment

People are constantly exposed to particulate matter and chemicals released during fires. However, there are still few studies on gas and particulate emissions related to exposure to burning firewood and charcoal during forest fires, making it difficult to understand the effects on the health of the population. The objective of this study was to quantify the metal(loid)s present in the smoke from wood and charcoal fires through the deposition of metals in beef topside and pork loin, considering the routes of skin exposure, inhalation, and ingestion, contributing to the understanding of metals in the increase of the risks of cancer and mortality associated with firefighting and children. The concentrations of metals [aluminum (Al), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), vanadium (V), zinc (Zn)] and metalloids arsenic (As) were determined by inductively coupled plasma-mass spectrometry (ICP OES) after microwave digestion. Moreover, we assessed the associated risk regarding the elemental intake of these elements through the smoke, using the hazard quotient (HQ), hazard index (HI), Total Hazard Index (HIt), and carcinogenic risk (CR). All samples had results for HQ and HIt < 1, indicating a non-potential health risk. However, the carcinogenic risks posed by As and Cr via the three exposure pathways (except for inhalation exposure to children and adults, and by Cr via ingestion and inhalation for children and adults) exceeded the standard threshold. In conclusion, continuous exposure of firefighters or children to smoke from fires containing high concentrations of heavy metals such as As and Cr can be harmful to health. The study used animal tissues; thus, new methods must be developed to quantify the concentration of heavy metals deposited in human tissue when humans are exposed to smoke from fires.

Increased chlorophyll-a concentration in Barra Bonita reservoir during extreme drought periods

Climate projections models indicate that longer periods of droughts are expected within the next 100 years in various parts of South America. To understand the effects of longer periods of droughts on aquatic environments, we investigated the response of chlorophyll-a (Chl-a) concentration to recent severe drought events in the Barra Bonita Hydroelectric Reservoir (BBHR) in São Paulo State, Brazil. We used satellite imagery to estimate the Chl-a concentration from 2014 to 2020 using the Slope Index (NRMSE of 18.92% and bias of -0.20 mg m^-3). Ancillary data such as precipitation, water level and air temperature from the same period were also used. Drought events were identified using the standardized precipitation index (SPI). In addition, we computed the probability of future drought events. Two periods showed extremely dry conditions: 1) January-February (2014) and 2) April-May (2020). Both periods were characterized by a recurrence probability of 1in every 50 years. The highest correlation was observed between Chl-a concentration and SPI (-0.97) in 2014, while Chl-a had had the highest correlation with water level (-0.59) in 2020. These results provide new insights into the influence of extreme drought events on the Chl-a concentration in the BBHR and their relationship with other climate variables and reservoir water levels. Drought events imply less rainfall, higher temperatures, and atmospheric dryness, and these factors affect evaporation and the water levels in the reservoir.

Drought-heatwave nexus in Brazil and related impacts on health and fires: A comprehensive review

Climate change is drastically altering the frequency, duration, and severity of compound drought-heatwave (CDHW) episodes, which present a new challenge in environmental and socioeconomic sectors. These threats are of particular importance in low-income regions with growing populations, fragile infrastructure, and threatened ecosystems. This review synthesizes emerging progress in the understanding of CDHW patterns in Brazil while providing insights about the impacts on fire occurrence and public health. Evidence is mounting that heatwaves are becoming increasingly linked with droughts in northeastern and southeastern Brazil, the Amazonia, and the Pantanal. In those regions, recent studies have begun to build a better understanding of the physical mechanisms behind CDHW events, such as the soil moisture-atmosphere coupling, promoted by exceptional atmospheric blocking conditions. Results hint at a synergy between CDHW events and high fire activity in the country over the last decades, with the most recent example being the catastrophic 2020 fires in the Pantanal. Moreover, we show that HWs were responsible for increasing mortality and preterm births during record-breaking droughts in southeastern Brazil. This work paves the way for a more in-depth understanding on CDHW events and their impacts, which is crucial to enhance the adaptive capacity of different Brazilian sectors.