Barrons AP Environmental Science

POINT SOURCE POLLUTION

Point source air pollution occurs when the contaminant comes from an obvious
source. For example, a certain factory is producing chemicals. As part of the
manufacturing process, certain poisonous chemicals and toxic gases result (e.g.,
benzene) and are released directly into the air.

NON-POINT SOURCE POLLUTION

Non-point source air pollution occurs when the contaminant comes from a
source that is not easily identifiable or from a number of sources spread over a
large, widespread area. For example, excess fertilizers, herbicides, and
insecticides from agricultural lands and residential areas are found in a river.

Point   Source  Pollution   vs. Non-Point   Source  Pollution

Point   Source  Pollution Non-Point Source  Pollution

Discharge   is  usually controlled  by

a   permit.

Many    small   diffuse sources from

many    different   locations.

Relatively  easy    to  control since

the type    of  contaminant and

location    are known.

Individual  contributions   are

smaller,    but cumulative  effects

may be  significant.

Fairly  easy    to  monitor above   and

below   the discharge   point.

Difficult   to  monitor;    many    stations

required.

The industry    can be  fined   if  it

does    not obey    the terms   of  the

permit.

Difficult   to  locate  and fine

offenders.

MAJOR AIR POLLUTANTS

Criteria Air Pollutants

Criteria air pollutants are a set of eight air pollutants that cause smog, acid rain,
and other health hazards. They are typically emitted from many sources in
industry, mining, transportation, power generation, and agriculture. They were
the first set of pollutants recognized by the U.S. Environmental Protection