Public Health and Environmental Conservation: Interrelated Fields
After about 15 years primarily spent in the public health sector, I told bewildered friends and colleagues that I was taking a “hard left turn” in my career. I left a job working for New York’s largest hospital system, and with that, a decent salary, a manager title, and probably the best benefits I will ever have, to serve as an AmeriCorps volunteer with a small stipend, no benefits, and a temporary/seasonal status. The deeper into the program I got, the more it became abundantly clear: It’s not as much of a “hard left” as I originally thought. Public Health and Environmental Conservation aren’t discrete disciplines, but rather completely intertwined.
It is no secret that the environment directly effects human health, and humans directly impact the environment, creating a constant feedback loop. As a Trail Steward, part of my responsibility was to educate people about Leave No Trace (LNT) principles. The most direct link between LNT and public health is, of course, waste management. We taught people to carry out human and dog waste when possible, or to responsibly bury it under 6-8 inches of soil and at least 200 feet from any water source (Leave No Trace, 2021). Aside from aesthetics, properly burying waste is important for mitigating the spread of harmful pathogens, such as E. coli or Giardiasis, for example. Stevenson, et al (2020) cite an overall lack of research within the public health realm regarding the impacts of human waste in the setting of outdoor recreation and express concern that it is an overlooked risk. They also reference studies demonstrating that pathogens can survive in fecal deposits for 6-12 months, depending on the environment, thus making them risky for humans and other animals that come in contact with them. Pathogens can leech into ground water and be carried to other areas, and in the age of antibiotics and hormones, which can be excreted, the contamination becomes even more problematic. So much so that some are advocating to do away with cat-holes and to promote packing out human waste instead (Langlois, 2022). Backcountry human and dog waste is both an environmental and public health issue.
Another big point of education was keeping people from wandering off the trails. On an individual level, this can directly affect safety of the individual; a simple browser search for risks of hiking off the established paths brings up dozens of articles about death and injury. On trail maintenance days, we engineered the physical environment to encourage staying on the trail. Connecting this with public health on a larger scale may seem a bit of a stretch, but stay with me. When we build a water bar and retread muddy trails, we are making an area more walkable, thus eliminating the development of social trails that degrade vegetation, promote the spread of invasive species, and encroach on natural habitats. Subtle visual design, direct cues (blazes, quality maps, etc.,) and education can help mitigate intentional and accidental off-trail travel (Martin & Butler, 2017). Treading off trails can be a vehicle for the spread of invasive species (Liedtke, et al, 2019) which degrades biodiversity and can increase human-pathogen contact. Take, for example, one of the invasive species that the Conservation Corps worked on last summer: Japanese barberry. This non-native plant has been shown to be a habitat for ticks and their hosts, thus impacting human health (ISAC, 2019). The second link has to do with methodology. In public health, I studied how the built environment—sidewalks, stairs, urban parks, etc.—are specifically engineered to encourage exercise and outdoor activity, thus promoting healthy behaviors. This, in combination with education about the importance of brushing one’s boots and staying on the trail, works to mitigate environmental impacts, thus having the downstream effect of protecting human health via protecting native ecosystems.
On a global scale, environmental pollution leads to more severe climate change, thus increasing the incidence of severe weather patterns. Stronger storms lead to more devastating erosion and degradation of the environment, which then increases the negative impacts to life (hurricanes, flooding, landslides) and the things needed to sustain it (crops, soil, trees, potable water). Zooming back in for a moment, off-trail travel degrades plants and soils, which can lead to erosion. This coupled with stronger storms and more intense weather can lead to landslides which can impact human populations. Climate change also has led to increased mating seasons and increased reach of populations of mosquitos and ticks (vectors), for example, which coupled with an expanding human population and encroachment on natural habitats of reservoirs (animals and environments that sustain vectors), is linked with increasing incidence and prevalence of known zoonotic diseases (malaria, lyme, etc.,) as well as emerging ones.