Translation 3

Translation 3: Letter to local (in this case Brazilian) politician

Dear [local official], 

It’s time to take deforestation seriously. Not only is this practice devastating the biodiversity and local land, but it’s now proving to have some serious consequences on public health. 

A recent study published in 2020 by Nawaz & Henze in GeoHealth investigated the relationship between biomass burning (deforestation) and public health, specifically how the emissions from biomass burning can be linked to premature deaths. Looking at data from Brazil between 2016 and 2019, the paper was able to conclude that there was a significant correlation between increased emissions and increase of premature deaths. First, it’s important to understand some background information. Deforestation, a common modern environmental issue, has many “obvious” impacts that are widely talked about. Aspects such as loss of biodiversity, land fragmentation, and emission of greenhouse gasses are all known to be effects of deforestation. One study from 2012 estimates that up to 17% of carbon dioxide emissions are from deforestation alone (Baccini et al., 2012). Since this study specifically looks at deforestation of the Amazon rainforest, it’s also noteworthy to mention that modern deforestation practices have been occurring in the Amazon since around 1912 and began to really increase in the 1970s (Pedlowski et al., 1997). 

The 2020 study by Nawaz & Henze, however, looked at how the emissions from deforestation – specifically biomass burning – can impact public health. They looked at fine particulate matter (PM2.5), which is a microscopic pollutant that is released from burning events. To put how small these particles are into perspective, the diameter of a human hair is about 70 micrometers. Fine particulate matter has an average diameter of 2.5 micrometers (hence the name PM2.5). Inhalation of PM2.5 that has been released into the atmosphere has been associated with premature death in previous studies (Burnett et al., 2014). This more recent study aimed to investigate premature deaths due to emission of PM2.5 from biomass burning events in Brazil between the years 2016 and 2019. 

Nawaz & Henze (2020) utilized data from two different sources to look at estimating emissions from biomass burning events. The first was Fire Inventory from NCAR (FINN). This dataset was collected using satellite observations which looks at the areas burned, comparing the difference before and after burning events and estimating the emissions from the estimated biomass burned. The other data, from Quick Fire Emissions Dataset (QFED), was collected in a much more complicated manner. This method used something called fire radiative power (FRP), which looks more at the energy given off from the emissions. Adjoint sensitivity analysis through the GEOS-Chem adjoint model was used to find the average sensitivity and apply that to a gradient of emissions across the area in a given time period. Using this data, they then used formulas to conduct a health impact analysis. They came to an equation that reads as:

(Premature mortality) = (Population of Brazil) * (Brazilian baseline mortality rate) * (attributable fraction of PM2.5 exposure)

These equations were run for each health outcome, which included: ischemic heart disease (IHD), stroke, acute lower respiratory illness (ALRI), lung cancer (LC), and chronic obstructive pulmonary disease (COPD). Since emissions data can be very uncertain, confidence intervals were run for the emissions data for every year. 

The results derived from this study are a bit complicated. First, it’s important to look at the trends of biomass burning emissions. Nawaz & Henze (2020) found that both the QFED and FINN data had elevated seasonal emissions when comparing the 2019 data to the 4 year average of emissions. In August and September of 2019, these values were 262% higher (Nawaz & Henze 2020). Looking closely at the temporal trends that are linked to premature mortality in the area, this study found that the fire emissions caused an average of 4,407 premature deaths per year. The most common health outcome linked to premature death from PM2.5 exposure was IHD, which represented 32% of the studied premature deaths (Nawaz & Henze 2020). 

Interestingly, the study also found that there was an importance on the spatial differences as well. This means that “the magnitudes of premature deaths are not solely dependent on the magnitude of emissions; this pattern is also observed in the spatial distribution” (Nawaz & Henze 2020). Emissions increased the most in western Brazil, which is an area composed mostly of forests, as opposed to an area made of a savanna. Additionally, they considered the difference in impacts of a densely populated region versus a remote area. They estimated that more PM2.5 exposure would occur from a small fire upwind of a densely populated area than a larger fire in a remote area (Nawaz & henze 2020). 

Overall, studies like this are important when considering all of the impacts that anthropological deforestation events are having on the environment. Yes, the most obvious impacts are important. However, impacts on public health, while possibly more difficult to observe and research, are equally important. Due to some limitations of this study (having only observed specific months, specific years and specific types of emissions), further research is required moving forward to understand the full scope of the health impacts of emissions from biomass burning events. Along with more research, it is imperative that stronger conservation efforts are put in place not only in areas such as the Amazon but in forests across the entire world to not only save biodiversity but – as this study shows – to mitigate the impacts on human health. Stricter regulations leading to a serious decrease in the rate of deforestation across the globe are necessary. However, on a local level, with your help we can start pushing for change that will hopefully drive national changes. 

Works Cited

Baccini, A., Goetz, S. J., Walker, W. S., Laporte, N. T., Sun, M., Sulla-Menashe, D., Hackler, J., Beck, P. S., Dubayah, R., Friedl, M. A., Samanta, S., Houghton, R. A. (2012). Estimated carbon dioxide emissions from tropical deforestation improved by carbon-density maps. Nature Climate Change, 2(3), 182–185. https://doi.org/10.1038/nclimate1354

Burnett, R. T., Pope, C. A., Ezzati, M., Olives, C., Lim, S. S., Mehta, S., et al. (2014). An integrated risk function for estimating the global burden of disease attributable to ambient fine particulate matter exposure. Environmental Health Perspectives, 122(4), 397–403. https://doi.org/10.1289/ehp.1307049

Nawaz, M. O. & Henze, D. K. (2020). Premature deaths in Brazil associated with long‐term exposure to PM2.5 from Amazon fires between 2016 and 2019. GeoHealth, 4(8). https://doi.org/10.1029/2020gh000268

Pedlowski, M.A., Dale V.H., Matricardi E.A.T., Silva Filho E.P. (1997). Patterns and impacts of deforestation in Rondonia, Brazil. Landscape and Urban Planning, 38(1997), 149-157.