1-12 Sources of pollution

APES 2024

Point source

Point source

refers to a single, identifiable source of a pollutant,
such as a smokestack or water discharge pipe

Point source examples

• Animal waste runoff from a CAFO–ammonia, fecal coliform bacteria

• Emissions from a power plant-CO2, NOx, SO2, PM

• BP oil spill

Nonpoint source

diffused and can therefore be difficult to identify, ex. pesticide spraying and urban runoff

Urban runoff ex.

• motor oil

• nitrate fertilizer

• road salt

• sediment

Pesticides on agricultural areas

carried by wind and water into bodies of water

3 metals of particular concern

• Lead

• Arsenic

• Mercury

Lead

found in pipes and other materials in older construction

• Can be removed by filters

• Flint, Michigan

Arsenic

occurs naturally and through human activity such as mining and industry

• Carcinogen and endocrine disruptor

Highest amounts of arsenic in the US are in the

upper midwest and west

Lead can damage central nervous system especially

in children

Mercury

occurs naturally and through human activity, primarily burning coal

• When elemental mercury enters a waterway bacteria can convert it to highly toxic
  methylmercury (2022 frq)

Exposure usually from eating fish and shellfish

Mercury

Synthetic organic compounds

carbon containing, human made compounds that can enter the water supply through industry or when applied over a large area (agricultural)

Synthetic organic compounds ex.

pesticides, pharmaceuticals, military compounds and industrial compounds

Pesticides

usually kill a wide variety of pests and may kill nontarget species

Pesticide ex.

• Endosulfan which is designed to kill insects is lethal to amphibians

• Roundup is toxic to amphibians, may penetrate tadpole gill cells

Pharmaceuticals and hormones

approximately 50% of streams in US
tested had antibiotics and reproductive hormones
• In another study, average stream had 52 pesticides
• Tend to be low level

Military compounds

perchlorates used in rocket fuel can cause soil
contamination and can leach from soil into groundwater and persist for many years

Industrial compounds

chemicals used in manufacturing used to be disposed of directly into rivers and streams

Led to Cuyahoga river fire in Ohio (1952)

Industrial compounds

Polychlorinated biphenyls (PCBs)

industrial compound once used to manufacture plastics and insulate electrical transformers

• When ingested are lethal and carcinogenic

Polybrominated diphenyl ethers (PBDEs)

flame retardants added to construction materials, furniture, electronics and clothing
• Have been found in fish, aquatic birds, and human breast milk

Per and poly fluoroalkyl substances (PFAS)

flame retardant, nonstick pans, food packaging – found in ground and drinking water

Found in blood of almost all humans, can cause cancer and impact fetal development

Per and poly fluoroalkyl substances (PFAS)

Coal ash

• Can be a source of mercury, lead and arsenic

• Can attach to fly ash from smokestacks and be carried by wind and deposited far away

• Both fly and bottom coal ash are usually stored on site in ponds dug into soil and lined with plastic

• Ponds can leach into groundwater, causing lead, arsenic and mercury contamination

• Ponds can overflow and runoff into nearby surface water and fields

• Duke Energy in NC

Neurotoxins

disrupt the nervous systems of animals

Carcinogens

chemicals that cause cancer, cause cell damage

Mutagens

carcinogens that may cause damage to the genetic
material of a cell

Mutagen ex.

• asbestos

• radon

• formadldehyde

Allergens

chemicals that cause allergic reactions, may cause
breathing issues and possibly death

Allergen ex.

• Peanuts

• milk

• penicillin

• codeine