chapter 25 air pollution the youngest scientist kids on the frontline of asthma research

CHAPTER 25 AIR POLLUTION

THE YOUNGEST SCIENTIST

Kids on the frontline of asthma research

THE YOUNGEST SCIENTISTKids on the frontline of asthma research25

Learning Outcomes

At the end of this chapter you will know:• The main types and global impact of

outdoor air pollution.• The health, economic, and

ecological consequences of air pollution.• Strategies for reducing pollutants in

both developing and industrialized nations.

25 THE YOUNGEST SCIENTISTKids on the frontline of asthma research

Core Concept

Air-quality issues span the globe and have serious health effects for humans and other organisms. Pollutants can travel great distances—it is this reality that makes it necessary to use technology to reduce pollutants at the source.


TERMS TO KNOW:Asthma

Case: Asthmatic children in Los Angeles have been collecting data about air quality by wearing monitors that continuously sample levels of small particles and nitrogen dioxide in the air.

By breathing into a specially designed collection bag several time a day, their breath is assessed for nitric oxide—a chemical marker for airway inflammation.


TERMS TO KNOW:Asthma

Asthma is a respiratory ailment marked by inflammation and constriction of the narrow airways of the lungs.

It is also one of the most common chronic childhood diseases in the United States and other developed nations and a major cause of childhood disability. Leading cause of school absences Prevalence doubled from 1980 to the mid-

1990s 7 million children and 17.5 million adults

diagnosed

Outdoor air pollution has been under examination for many years25

The link between air quality and human illness was recognized in the 1930s when people in Belgium became sick and died as a result of trapped pollutants associated with a temperature inversion. A similar event occurred in England in the 1940s when acid aerosols became trapped in the atmosphere, killing 4000 people.

The World Health Organization (WHO)

recognizes air pollution as a major threat to human health.

Outdoor air pollution in urban areas is responsible for at

least 1.3 million deaths annually. Indoor air pollution

may be responsible for 2 million or more premature

deaths per year.


Air pollution comes from: Vehicle exhaust Industry emissions Coal-fired power plants Indoor burning of solid fuels

(charcoal, wood, animal waste) Natural sources (sandstorms,

volcanic eruptions, wildfire)

Primary air pollutants – Directly release from stationary or mobile sources

Secondary air pollutants – When a primary pollutant reacts with other chemicals to form another pollutant.

Controlled burning of agricultural fields


Air pollution comes from: Vehicle exhaust Industry emissions Coal-fired power plants Indoor burning of solid fuels

(charcoal, wood, animal waste) Natural sources (sandstorms,

volcanic eruptions, wildfire)



Ground-level ozone and acid rain—pollutants from burning fossil fuels react with atmospheric oxygen in the presence of sunlight.


Air pollution regulation:Standards for particulate matter (PM) and six “criteria pollutants” Sulfur oxides Carbon monoxide Nitrogen oxides Ground-level ozone Lead



Ground-level ozone and acid rain—pollutants from burning fossil fuels react with atmospheric oxygen in the presence of sunlight.


In addition to the six criteria pollutants, the EPA also recognizes 187 hazardous air pollutants that can have adverse effects on human health.

Carcinogens Teratogens Pollutants affecting

central nervous function and other body tissues

Volatile organic compounds (VOCs)

Polycyclic aromatic hydrocarbons (PAHs)

CO2

Outdoor air pollution has many sources25

25Analysis of blood taken from

children with severe asthma in California showed a difference in

the regulating cells—a critical component of the immune system

—in asthmatic children.

Those kids with the changes in their “peacekeeping cells,” the cells that would normally keep inflammation

at bay, also had higher levels of pollutants in their blood.

It appears that certain air pollutants stifle the activity of

genes responsible for maintaining normal immune-system function.

Students in the South Bronx were twice as likely to attend a school near a highway as were children in other parts of the city. The South Bronx is home to some of the highest asthma hospitalization rates for children in New York City.

The air we breathe affects our lungs, especially those of children

The air we breathe affects our lungs, especially those of children25

Minority communities still face more exposure to pollution than

average—an example of environmental racism.

The risk for developing cancer from exposure to polluted air increased

as income decreased.

In general, cancer risk is higher for minorities, regardless of income

level.

Children of low-income families are especially at risk since their homes

are often near major roads or factories, and they often come

from and go to school when traffic is heaviest.

Students in the South Bronx were twice as likely to attend a school near a highway ad were children in other parts of the city. The South Bronx is home to some of the highest asthma hospitalization rates for children in New York City.

Traveling pollution has far-reaching impacts25Air pollution doesn’t stay where it begins. Sulfur and nitrogen emissions react with oxygen and water to form acid rain and snow. Falling acid rain acidifies the soil, setting off another sequence of unfortunate events.

Traveling pollution has far-reaching impacts25

Restrictions imposed by the Clean Air Act have helped decrease acid deposition in the United States. Smokestack scrubbers remove sulfur from coal burning, reducing SO4 released. Emission-control technologies on vehicles, such as the catalytic converter, convert dangerous combustion by-products to safer emissions.

Though acid deposition has

decreased, surface waters

and soils remain acidic due to the accumulation of

acids over the years and

ecosystems have not yet shown

signs of recovery.

Indoor air pollution may pose a bigger health threat than outdoor air pollution25

Mold, pollen, mites, hair, and dander


Particulates


Chemicals

Air pollution is responsible for myriad health and environmental problems25

Air pollution does not respect political boundaries—regulation requires

international cooperation. Scientists are discovering plants around the world

under stress from pollutants released from industrialized nations.

Trees inside a controlled environment are used to study the effects of air pollution on plants. These trees show damage from excess ground-level ozone. Acid rain has stunted growth of these conifers

at high elevations in the Austrian Alps.

We have several options for addressing air pollution25

Command and Control Regulation – Setting national limits for allowable levels of pollution with fines for non-compliance. • Clean Air Act (USA, 1963) – Set air-quality

standards that each state was responsible for enforcing.• Green taxes – Taxes on environmentally

undesirable actions.• Tax credit – Reduction in taxes based on

environmentally beneficial action.• Subsidies – Money or resources intended to

promote environmentally friendly activities.• Cap-and-trade – Limits to the amount of

pollution allowed but with an opportunity to sell or trade unused permits.

Erosion exceeding normal weathering likely from acid

rain is being seen in national treasures around the world.

Statue in Trafalgar Square, London


Technology and policy can help curb air pollution: filters and ventilation systems to improve indoor air;Reducing emissions from manufacturing with end-of-pipe solutions. Filters Electrostatic precipitators Catalytic converters Scrubbers Cap-and-trade


Technology and policy can help curb air pollution Filters and ventilation systems to improve indoor airReduce emissions from manufacturing with end-of-pipe solutions Filters Electrostatic precipitators Catalytic converters Scrubbers Cap-and-trade


Mass-transit options that decrease the number of cars on the road will reduce air pollution.

Buses that run on compressed natural gas emit fewer emissions overall, but the particulates they release are very small, so—while better than a traditional diesel bus—they are still not pollution free.

PERSONAL CHOICES THAT HELP25

UNDERSTANDING THE ISSUE25

ANALYZING THE SCIENCE25

EVALUATING NEW INFORMATION25

http://www.stateoftheair.org

MAKING CONNECTIONS25

chapter 25 air pollution the youngest scientist kids on the frontline of asthma research

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