-: Welcome to week one of PH304,
Environmental Public Health.
In this presentation, we'll review some of the topics
covered in your reading, and also discuss other ways
to think about the field of environmental health.
Your textbook introduced you to several different
definitions of the environment and environmental health.
The definition of the environment
that is most inclusive is probably the one shown here,
and includes all of the external factors that act on humans.
Note that this definition is probably not the same
as one that would be used by an environmental scientist
or an environmental engineer, especially because it refers
to those factors that act on humans.
This is specific to a health context.
In terms of definitions of environmental health,
many are quite broad.
The one shown here was provided in your textbook,
and is from the World Health Organization.
Let's take a moment to break down this definition.
First, this definition includes quality of life,
so that would include things
that make people's lives better, like housing quality,
or even access to nature, and not just the bare necessities.
The definition also refers to physical, chemical,
biological, social and psychosocial
factors in the environment.
This indicates a very broad range of potential exposures
that fall under the umbrella of environmental health.
Everything from ergonomic chairs, noise, radiation,
pesticides sprayed on farm fields,
certain infectious diseases,
urban planning, transportation, land use,
and systematic racism are all included in this definition.
The definition also refers to the theory and practice
of assessing, correcting, controlling and preventing
those factors in the environment,
so that's really getting at what the field
of environmental health is, that can potentially affect
the health of present and future generations.
I think that it is really important
that future generations are noted in the definition.
Take a moment and think of one or two
environmental health impacts that we might
be concerned about for future generations.
A prominent example that comes to my mind is climate change.
Future generations will have to contend
with higher temperatures in some areas,
more severe storms, and other health risks
as a consequence of climate change.
Another example that comes to mind
is when pregnant women are exposed to toxins.
It raises the question of whether
or not the baby will be harmed.
We know that some chemicals can pass
to the fetus through the umbilical cord,
but there's also evidence that some chemicals
can alter gene function, and that this can be passed
down to subsequent generations,
so not just from mother to child, but that child could
potentially pass it on to their future children.
Sometimes it is easier to think about environmental health
in terms of the range of different environmental media
that people can be exposed to health hazards through.
For example, ambient air pollutants,
including particulate matter, ozone,
and volatile organic compounds
can adversely affect human health,
especially cardiovascular and respiratory outcomes.
Water pollutants can include infectious diseases
like schistosomiasis and giardiasis,
chemicals, including metals like lead and arsenic,
or organic compounds such as those found in pesticides,
and then soil pollutants can also be hazardous.
Think for example, Superfund sites
and hazardous waste sites, and exposure can often vary
by race or socioeconomic status,
so this is an important environmental justice issue as well.
The indoor environment can also become
contaminated and impact human health.
Things like secondhand smoke, mold,
pest infestations, allergens and toxins
can all impact health in that environment.
The last two things on this list,
environmental safety and unintentional injuries
and physical hazards, aren't necessarily media
or location specific, but fall under the environmental
and occupational health umbrella nonetheless.
Unintentional injuries are one of the leading causes
of deaths for persons aged one to 24 years in the US.
And that includes falls, cuts, burns,
motor vehicle accidents, and other things.
Physical hazards can include noise, ionizing radiation,
and ergonomics, so even the setup of your office.
The text mentioned several emerging
issues in environmental health,
and I've outlined those and a few others here.
First, I think that there's been increasing recognition
of chemical hazards, and that was highlighted
by the Lautenberg Chemical Safety Act
that was signed into law in 2016.
The Lautenberg Chemical Safety Act amends
the Toxic Substances Control Act, or TOSCA,
the nation's primary chemicals management law.
The new law included some important improvements,
such as mandatory requirement for the EPA to evaluate
existing chemicals with clear and enforceable deadlines,
risk-based chemical assessments,
and increased public transparency for chemical information.
There's also been a recent push to acknowledge
the health benefits of natural spaces and time in nature,
particularly in urban environments,
where it can be harder to access such spaces.
There's also been a growing
awareness of the interconnectivity
of human health and the environment.
There are a couple different emerging fields,
including ecohealth, one health and planetary health,
which all address this issue in slightly different ways.
Environmental justice was born
out of the combination of public health
with the civil rights and environmental movements.
In the United States, Black communities have
been disproportionately located
near environmental hazards such as toxic waste sites.
Internationally, environmental injustice is evident
as people in low income countries are exposed
to toxic materials and chemicals
during the salvaging and recycling of e-waste,
most of which is from high income countries.
we'll actually return to this example a little bit later.
Climate justice is similar in that those people
who are producing the vast majority of the greenhouse gases
fueling climate change are not the same people who are most
likely to suffer from the effects of climate change.
Scientific advances are changing the science
and practice of environmental health.
Molecular tools, including genomics,
provide insights into gene-environment
interactions at the population level.
Researchers are taking advantage of new
sources of data as well, for example mining social media.
Global change, including human population growth,
loss of biodiversity and species extinction,
globalization, urbanization, economic inequities,
pollution, land use change, climate change,
and conflict and displacement all present
massive challenges to environmental health.
As such, there is increased focus on sustainability,
which according to one definition is the ability
to meet current needs without jeopardizing
the needs of future generations.
Environmental factors can impact health
on a wide variety of spatial scales,
so I wanted to touch on that quickly here.
For example, radiation can make
changes at the molecular level.
A chemical hazard may interact at the cellular level.
A foodborne pathogen affects a person or an organism.
Your workstation and your immediate surroundings
can be either protective or increase
your risk of ergonomic injury.
Multiple factors, for example, wood stoves,
can affect the indoor air quality in your home or building.
Sidewalks and bike paths make a neighborhood walkable.
Affordable and reliable public transportation can reduce
metropolitan transportation related air pollution.
Emergency planning for New England
includes planning for flood and ice storms,
two of the natural disasters to which
we are susceptible in this region.
Global treaties are needed to reduce carbon emissions
in order to mitigate the most serious
impact of climate change worldwide.
Of course, I've mentioned these spatial scales in isolation,
but some environmental factors work at multiple scales.
The foodborne pathogen acts at a cellular level in the gut
to cause systemic illness in an organism, in a human.
Pollution from a coal-fired power plant
in one metropolitan area may cause
regional pollution due to prevailing winds.
So just bear that in mind as we continue
to study environmental health hazards.
Another important consideration that we've touched
on briefly in this presentation is that often environmental
health impacts can be displaced in time and space.
Generally, wealthier individuals and groups
have the ability to distance the themselves spatially
and temporarily from the ecological consequences
of their consumption choices, and the impacts
are often shifted to resource poor populations
that are more vulnerable to the adverse consequences.
For example, toxic e-waste, including old phones,
laptops, toys, and other devices
from high income nations is often shipped, whether legally
or illegally, to low income countries.
E-waste can contain hundreds of different materials
and contain toxic substances like lead,
mercury, arsenic and flame retardants.
Once in a landfill, these substances
can leach into the environment.
This is an example of the spatial displacement
of potential impacts, where we are literally moving
the environmental hazard from one location to another.
Climate change is actually a great example
of temporal displacement of environmental health impacts,
because many of the impacts will
be felt by future generations.
The links between environmental change and public health
are often clearest in poor communities,
but wealthy communities can't completely
avoid all of the adverse impacts.
To wrap up this brief introduction to environmental health,
I wanted to leave you with a list of a few resources
that you might find helpful throughout the semester.
The first is the National Institute
of Environmental Health Sciences, and I suggest
that you Google this and visit their website.
Also, the CDC'S National Center for Environmental Health,
and the WHO's Environmental Health website.