Translation 2

Translation 2: Intro to ES course material at a liberal arts college

Case Study: Deforestation impacts on public health and premature deaths 

Introduction: 

Deforestation can come in many forms, whether it’s cutting down trees or a form called biomass burning. In any case, this practice has many negative environmental impacts such as loss of biodiversity, habitat and land fragmentation, and an increase in carbon dioxide into the atmosphere. Forests act as carbon sinks, meaning they absorb carbon dioxide from the atmosphere and contain it. However, when more and more forests are cleared, we are left with fewer areas for carbon to be absorbed. Additionally, the process of biomass burning itself releases carbon dioxide and potentially other greenhouse gasses into the atmosphere. A study from 2012 estimated that up to 17% of carbon dioxide emissions come from deforestation (Baccini et al., 2012). 

A recent study published in 2020 by Nawaz & Henze observed impacts from

deforestation that are more difficult to see first-hand. These impacts on public health include premature deaths from an increase in fine particulate matter, or PM2.5, coming from the emissions from biomass burning events. Nawaz & Henze (2020) focused on Brazil, which has a long history of deforestation, specifically in the Amazon. They chose to study the years from 2016 to 2019 and look at how different rates of emissions from biomass burning events correlated to rates of premature deaths from related illnesses. 

Methodology: 

The methodology for this study is rather complex, and relies on a decent amount of modeling. First, though, it’s important to look at the two main datasets utilized by the study. The first is 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. For this data, they used something called adjoint sensitivity analysis to account for uncertainties and create a more accurate gradient of emissions. 

When looking specifically at the rates of premature deaths, an equation was used to analyze each disease that was considered. 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. 

Results: 

• Both the QFED and FINN data had elevated seasonal emissions when comparing the 2019 data to the 4 year average of emissions

  • QFED tended to be consistently higher in its emissions approximations

• Fire emissions caused an average of 4,407 premature deaths per year, with the lower limit being 1,302 and the upper limit being 9,550

• The most common health outcome linked to premature death from PM2.5 exposure was IHD, which represented 32% of the studied premature deaths

• Averages differed slightly between each year’s seasons, with 2017 being the highest and 2017 being the second highest

• Emissions increased the most in western Brazil, which is an area composed mostly of forests, as opposed to an area made of a savanna

  • More PM2.5 exposure would occur from a small fire upwind of a densely populated area than a larger fire in a remote area

Conclusion: 

This study confidently connected emissions from biomass burning events to effects on public health, most commonly increases in respiratory or cardiopulmonary diseases. While this study only focuses on certain months for a couple years in one country, more research is needed to create a stronger foundation for these types of conclusions. However, it is an important first step in addressing another harmful side-effect of anthropogenic deforestation. Going forward, it is imperative to increase conservation efforts, not only for the sake of biodiversity but also for public health. 

While this is your first semester in environmental studies, it’s important to start looking at these complex issues now. Whatever focus you decide to take in this discipline, every aspect of the environment is connected in some way. Who knew that the fine particles smaller than the diameter of a piece of hair from biomass burning were causing premature deaths? Issues like this are exemplary of the liberal arts curriculum we create here. The biological, chemical and physical sciences are insanely important in responding to issues like this. Just as important, though, are disciplines like communication (to relay the findings and mitigation strategies) and other behavioral sciences such as psychology and sociology (to investigate how these complex issues impact individuals and societies). Going forward, you’re going to be challenged to look at these issues from multiple perspectives, especially in a discipline that is as interdisciplinary as environmental studies. 

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

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