An Overview of Air, Water & Soil in Agriculture

Barbara McCarthy, Ph.D.Environmental Health Department

Colorado State University

Agriculture & Environmental Health

• Agriculture is not part of “classical” Environmental Health (EH)

• EH as an aspect of public health– air, water, food, shelter important as related

to:• communicable disease transmission• toxic chemical exposure• physical agent interaction

Agriculture & EH

• Agriculture’s importance relegated to – diseases associated

with agricultural chemicals

– production of an ample and proper diet

EH Definition

• Protection against environmental factors that may adversely impact human health or the ecological balances essential to long-term human health and environmental quality.

(NEHA, 1996)

Ecological Balances

• Odum’s proposed Life-Support System– Life-Support environment– Organisms– Processes– Resources

• Providing human physiological necessities

Ecological Balances

• Life-Support Environment– Cultivated landscapes– Domesticated landscapes– Natural landscapes

• Provide food, mineral nutrients, air, water

Ecological Balances

• Urban & Industrial landscapes are NOT included in life-support environment.

– energy demanding– pollution generating

Ecological Balances

• The larger the urbanized area, the greater is the need for natural and domesticated landscapes.

– supporting host role

Domesticated Landscapes

• Include agricultural lands

• Dominated by cultured plants and domestic animals

• Produce food and fiber

Domesticated Landscapes

• Crucial in helping to provide: – healthy soil– clean water– diverse habitats

that promote the necessary ecological balances

US Land Use

• About 50% of US land is privately owned and classified as: -cropland

-pastureland

-rangelandUSDA, Natural Resources Conservation Service, 2001

US Land Use -- Cropland

USDA, Natural Resources Conservation Service, 2001

Each green dot represents 25,000 acres

US Land Use -- Grazing Land

USDA, Natural Resources Conservation Service, 2001

Each dot represents 25,000 acres

US Land Use -- Farmland Loss

• On the average approximately 645,000 acres of prime farmland is estimated as lost to development per year from 1992 - 1997

Water Demand & Precipitation

Legend: Percentage of Local Average Annual PrecipitationUSDA, Natural Resources Conservation Services, 2001

Greater than 150% 100% to 150% 75% to 100% Less than 75%

Excessive Cropland Erosion

Legend: Each red dot represents 5000 acres of highly erodible land and each yellow dot represents 5000 acres of non-highly erodible land with excess erosion above the tolerable soil erosion rate.

USDA-Natural Resources Conservation Service, 2001

Water Quality -- WQ Inventory

• National Water Quality Inventory– completed every TWO years– required by the Clean Water Act– evaluates a subset of US

• rivers & streams (23%)• lake, reservoir, pond acres (42%)• Great Lakes shoreline miles (90%)

Water Quality -- WQ Inventory

• Agricultural use fully supported by:– 97% of river & stream miles– 89% of lake, reservoir, pond acres– 100% of Great Lakes shoreline miles

• All uses supported by:– 65% of river & stream miles– 55% of lake, reservoir, pond acres– 4% of Great Lakes shoreline miles

Water Quality -- WQ Inventory

• Ag activities were reported as the most widespread pollution source

• silt• nutrients

Water Quality -- NAWQA

USGS program using consistent, standardized methods to assess water quality.

Water Quality -- NAWQA

• Water quality information used in understanding impacts of human activity and natural factors.

• Synthesis with climate, soils, geographic, geologic, hydrologic information.

• Nutrients and pesticides evaluated.

Water Quality -- Pesticides

• Analysis• 1992 - 1996• 76 pesticides• 8200 samples

• Most extensive data to date

• Results• 58 pesticides

detected• >95% surface

water positive• <50% ground

water positive• >50% ag and

urban streams exceeded guideline

Water Quality -- Nutrients

• Nitrogen– elevated levels in ag

and urban areas– highest

concentrations in agricultural areas

– 15% groundwater samples > EPA nitrate standard

• Phosphorus– elevated levels in ag

and urban areas– highest

concentrations in urban areas

– tends to attach to soil and not contaminate groundwater

Water Quality -- NAWQA

Results of the USGS program support the stated general

agricultural impacts as reported in the Water Quality Inventory.

Ecological Balances

Domesticated landscapes are crucial in helping to provide healthy soil

clean water

diverse habitats

that promote the necessary ecological balances.

Ecological Balances

• As exemplified by the familiar problems of water quality degradation due to

• erosion• pesticide runoff• nutrient inputs

agricultural lands are an additional burden on remaining landscapes.

Ecological Balances

• Key to change lies in viewing agricultural lands as parts of larger regional systems that provide life-support.

Ecological Balances

Challenge• to capture the NRCS vision• to translate into local action

…farmers and ranchers produce much more than food and fiber. Through their care and stewardship of the land, farmers and ranchers produce safe drinking water, clear-flowing streams, lakes full of fish, skies full of ducks

and geese, and scenic landscapes.

Life-Support Vision

• Life-support vision for agriculture is fundamental to providing the ecological balances essential to long-term human health.

• EH professionals are clearly called to an expanded involvement in agriculture issues.

EH Professional’s Role

• US does not have an EH system but a “web of organizations”.

• Trend toward decreasing environmental responsibilities of state health agencies.

• Environmental protection to state regulatory agencies

EH Professional’s Role

• Regulatory focus does not encourage an improved understanding of the important, life-supporting relationship between the environment and human health.

• Funding is focused on regulatory activities not EH activities.

EH Professional’s Role

• EH programs include:– epidemiology– risk assessment– environmental sanitation

• EH activities include:– education– surveillance

EH and Agriculture

• EH & Agriculture Connection– fundamental

• Provision and maintenance of a life-supporting environment.