It’s nice for family and friends to have some idea of what you spend your days (and student loan money) doing. So what the heck I’m doing in grad school specifically? It always seems so nebulous when I try to explain it. Mainly people ask: how is public health different from medicine? Public health is about identifying and preventing the causes and consequences of illness and disease on a population level. Medicine is what you need on an individual level after you become ill. They often overlap, but ideally we want to reduce sickness and the need for medical treatment.
Environmental health specifically is the interaction of the natural, built, and social environment and public health. More than just focusing on naturally occurring chemicals or diseases, the department is increasingly focusing on urban planning, climate change, socioeconomic factors, food production, and air pollution, to name a few.
School: Johns Hopkins Bloomberg School of Public Health
Degree: Master of Health Science
Certificate: Risk Sciences and Public Policy
Department: Environmental Health Science
Track: Population Environmental Health
Core elements: environmental science, epidemiology, toxicology, risk sciences, biostatistics, human physiology
This is actually the hospital and medical school, but my building is right next door.
Here is a useful diagram that gets put into every lecture in every public health class I’ve ever taken:
Toxicology: the study of toxins and how they affect human health. This includes characterizing substances like chemicals, elements, and pollutants by their physical properties (e.g. whether they are polar is extremely important) and how they cause disease and cancer biochemically. Cell biology, DNA, metabolism, physiology, etc. Example slide from lecture of how alcohol affects the liver:
Epidemiology: We learn how to design studies that will help us measure and infer the distribution, causes, prevention, and control of diseases in populations. These can be, for example, studies of a people assigned to a treatment or placebo (randomized controlled trial/clinical trial), or large numbers of people that are followed through time to see what exposures lead to what outcomes (cohort study). We learn about how to measure and compare outcomes between different exposure groups and how different variables interact to produce health effects. Things get very complicated. Example lecture slide about how we begin to calculate the incidence of a disease in a study population from an introductory course:
Biostatistics: the tools of public health. Statistical analysis is how we decide whether public health studies show us an association between factors and disease. We use, for example, probability concepts (like odds of exposure & disease, normal (z), t, and F probability distributions), linear regressions (simple, multivariate), etc. Epi and biostats are like brother and sister. Example slide about using sample measurements from a population:
Risk Science: The paradigm of risk assessment goes from characterizing the hazard and its dose-response (toxicology), to quantifying the exposure (epidemiology). To then assess the risk in the population, you can use formulas to estimate how many excess deaths or cancer cases will occur in a given population (e.g. the U.S.) from this exposure. This field also includes communicating risk to the public and lawmakers and incorporating it into legislation to protect public health (think EPA regulations like the Clean Air Act, Clean Drinking Water Act, etc. that dictate maximum levels of contaminants that are allowed into public water & air). Hopkins offers a separate certificate for this sequence that happens to correlate well with the classes I’m already taking for my degree, so I’m getting a bonus certification, basically. Example introductory lecture slide about dose-response:
Environmental Science: Environmental chemistry, earth science, botany, hydrology, geology, atmospheric science, etc., as they relate to public health. For example, how is ground-level ozone pollution (smog) formed from vehicle exhaust (nitrogen oxides and hydrocarbon particulates) and sunlight? Climate change is a huge part of this discussion in public health because it exaggerates climate extremes and alters the hydrology and atmosphere of the planet. This creates, for example, more urban heatwaves, droughts, heavier monsoons, melts glaciers, and decreases available fresh water. Example lecture slides from introductory classes:
International Health: As you may know, I have big dreams of working internationally. My department does not have much of an international focus, but I’m ok with that, because my degree teaches scientific skills that I wouldn’t be able to get from the more theory-based International Health department, and I’ll be better able to apply what I know in an international setting. I’m taking a few classes that will help integrate my education with knowledge about developing countries.
What do I want to do after I graduate is always the #1 question, and as usual, my #1 answer is: I DON’T KNOW! I’ve already started applying to a bunch of summer gigs, internships, fellowships, and jobs that range from the U.S. to South America to Africa. It will depend on what I am qualified for and what organizations I apply to. I’m pretty open, so I don’t stress too much about my direction. The important thing is to try to be of some help to other people and my discipline before I die. Overall I love this school and I (almost) wish my program were longer than one school year.