APES Unit 8.14 Pollution and Human Health

A city's public health department has a limited budget and must

choose between two initiatives:

1. Repairing a wastewater treatment plant that is leaking

untreated sewage into a recreational lake.

2. Implementing a mandatory 'No-Idle' zone and subsidized

public transit to reduce tropospheric ozone during the

summer months.

Task: Defend which initiative would provide a more immediate

and measurable improvement to community health. In your

defense, contrast the biological nature of dysentery with the

chronic respiratory impacts of ozone, and explain why the 'cause

and effect' is statistically easier to track for one over the other.

Repairing a wastewater treatment plant that is leaking untreated sewage into a recreational lake would be a more immediate and measurable improvement to community health because it is harder to enforce a “no-idle” zone then repairing a plant.

Dysentery are more likely to face immediate death compared to lung damage caused by respiratory impacts of ozone.

Wastewater is easier to explain its cause and effect because ozone diseases can be caused by multiple factors, but wastewater can be tracked through pipes leading to homes or buildings.

Why do we have to do research in order to try to figure out which pollutants are causing health effects to humans?

It difficult to establish a cause and effect between pollutants and human

health issues because humans experience exposure to a variety of

chemicals and pollutants

• Sometimes we are aware of the exposure, but other times we are not

What are the 2 types of studies we conduct?

1. Retrospective studies

2. Prospective studies

Retrospective studies:

Monitor people who have been exposed to an environmental hazard such as

harmful chemicals, at some point in the past

What do the scientists specifically do during retrospective study?

Scientists identify a group of people who have been exposed to a

potentially harmful chemical and a second group of people who have not

been exposed to the chemical

• Both groups are monitored for many years to see if the exposed group

experiences more health problems than the unexposed group

Asbestos Study

People exposed to asbestos were developing a number of deadly diseases including asbestosis (painful inflammation of the lungs) and several types of cancer including mesothelioma

• Mesothelioma = inhaling or swallowing asbestos fibers

Untreated Sewage Study

By examining groups of people who were exposed versus not exposed to raw sewage….

➢ We learned that exposed people can be exposed to a variety of harmful chemicals and

pathogens that have led to an increased emphasis on sewage treatment throughout the

world

Dysentery

➔ An infection of the intestines that cause diarrhea, which results in dehydration and can

cause death

- Untreated sewage contains bacteria (E. coli, Salmonella), viruses (Hepatitis A), and

parasites/worms that cause gastrointestinal illnesses.

- Cholera is caused by a bacteria (Vibrio cholerae) which is a leading cause of dysentery

- Shigellosis (bacillary dysentery) is common, causing intense diarrhea, fever, and stomach pain.

Tropospheric Study

Individuals exposed to this pollutant are more likely

to experience increasing lung damage

➔ Including emphysema, bronchitis, and asthma -

compared to those not exposed to the ozone

Prospective Studies

Monitor people who might become exposed to an environmental hazard, such

as a harmful chemical, at some point in the future

What do the scientists specifically do during prospective study?

Scientist might select…

➔ A group of 1,000 participants and ask them to keep track of the food they eat,

the tobacco they use, and the alcohol they drink over a period of several

decades

As time passes, researchers can determine if the habits of the participants are

associated with any future health problems

➔ Is tricky because a participants habits (like tobacco use) can also be

associated with many other risk factors, such as socioeconomic status