Chapter 15 Pollution of Soil, Water, and Air

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Chapter 15 Pollution of Soil, Water, and
Air 151 Important Facts to Know

• Current status and activities and conditions
  that threaten the environment.
• Environmental threats and challenges.
• Kinds, sources, and interactions among plant,
  soil, water and air pollution.
• Kinds and extent of damage impacts.

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152 Threats to the Environment

• Perceptions vary from place to place and time to
  time, and are strongly influenced by human
  nature.
• Loss of biodiversity
• Modifications of landscape climate
• Over-exploitation of natural resources
• Non-native invasive species
• Water pollution
• Soil degradation

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153 Terminology

• Acceptable Daily Intake amount of material
  (plus a safety margin) that is safe to injest
• Acute Toxicity symptoms are rapidly exhibited
• Antagonism one substance reduces the
  detrimental effects of another
• Bioaccumulate increased concentrations are
  accumulated over time (food chain)
• Carcinogenic the potential to cause cancer in
  humans
• Chlorinated Hydrocarbons organic pesticides
  with chloride groups attached to carbon groups
  (DDT, Chlordane, etc.)

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• Chronic Toxicity symptoms develop slowly over
  time
• Eutrophic water overly enriched with nutrients
  and often depleted in oxygen
• Food Chain material sequentially transferred
  through many organisms, one being food for the
  next
• Half-Life the time for half of a substance to
  be destroyed, inactivated, or lost
• Heavy Metals high atomic weight metals which
  are toxic to animal life
• Mutation a random gene change

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• Reference Dose - level of daily exposure that
  has no known negative effect
• Risk-Benefit Analysis evaluation of toxins and
  their permitted residue levels
• Synergism two factors interact causing a
  greater effect than if acting separately
• Teratogenic causes tissue transformations
  resulting in birth defects
• Threshold Level maximum level of a substance
  tolerated without inducing ill effects

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• Total Maximum Daily Load - regulatory maximum
  amount of pollutants allowed in water also known
  as too many damned lawyers
• Xenobiotic substance foreign to natural
  systems and are often persistent once present

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154 Plant Nutrients

• Eutrophication of surface waters
• Overabundance of nutrients causing accelerated
  algae and water-plant growth
• Usually N P (but there are others)
• Local examples?
• Results in decreased clarity and low oxygen
  content
• Sources fertilizers, municipal sewage, urban
  stormwater runoff, erosion, atmospheric deposition

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• Nitrogen in groundwater/methemoglobinemia
• Nitrate (NO3-) is very soluble, as an anion is
  not readily adsorbed by the soil, and is easily
  leached
• Sources include excessive fertilization,
  feedlots, municipal discharge, natural organics
  and septic systems
• Becomes toxic in humans and animals when reduced
  to nitrite in their digestive system and oxidized
  oxyhemoglobin to methemaglobin (anoxic) blue
  babies.
• Health standard 10 mg/L NO3-N (45 mg/L NO3-)
• Non-degradation vs zero discharge

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155 Organic Wastes

• Wastewater Land Application
• rapid infiltration, overland flow (slow rate
  infiltration), crop production
• nutrient loading, crop water requirements
• Sewage Sludge Land Application
• trace element (heavy metal) loading, pathogenic
  organisms (Tables 15-1 and 2)
• Livestock Manure
• highly variable nutrient concentrations content
  is different today compare to the past

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• Municipal Garbage, Composts, and Sanitary Land
  Fills
• Food Processing Wastes (cooking oil)
• Disposal is rapidly becoming a major issue

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156 Pesticides

• What constitutes a good pesticide?
• Short lived in the environment (a few days to a
  few weeks, does not bioaccumulate)
• Not carcinogenic, teratogenic, or mutagenic
• Effective and practical to use (oxymoron?)
• Example
• DDT is very effective, highly practical,
  inexpensive but also highly persistent,
  bioaccumlates and is biomagnified
• What about synthetic organophosphates?

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• Problems and Extent of Pollution
• Increased Resistance Dictates the need for new
  and stronger materials
• Erosion and Water Quality Degradation
  Particulate transport and deposition direct
  runoff and infusion into surface waters

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157 Heavy Metals
Examples mercury, lead, cadmium, chromium,
nickel, zinc, selenium, etc. Typically immobile
in soils, but some can be readily absorbed by
plants while others can be directly ingested from
particulate deposition (e.g., lead humans and
waterfowl)
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158 Natural Toxins

• Not all toxic substances are of anthropogenic
  origin.
• Common toxic range plants include locoweed,
  halogeton, saltbush, goldenweed, larkspur,
  lupine, princes plume, and woody aster.
• Soil Selenium too much or too little in forage
• Excess Mo Molybdenosis
• Pine Needles Abortions and pre-mature deliveries

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159 Particulates and Gases

• Lead Contamination Associated with leaded
  gasoline, lead pipes, etc on the decline
• Burning Agronomic uses such as weed and pest
  control, fuels management PM 2.5 and PM 10
  concerns, also surface water and lake pollution
• Acidic Rain and Fog Nitric and sulfuric acids,
  associated with highly industrial areas, power
  plants reduces soil pH and can cause direct
  damage to plant tissue

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• Ozone Depletion/Enrichment Ozone layer shields
  out UV radiation, depletion allows UV rays to
  penetrate the atmosphere enrichment near the
  earths surface is toxic
• Greenhouse Gases Carbon dioxide, nitrous
  oxide, methane result in heat entrappment and is
  presumably a contributor if not the cause of
  global warming.
• Is global warming a natural process that cycles
  periodically over time? If so, are we
  contributing to the frequency and magnitude?

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1510 Radio Nuclides
Radioactive elements emit high-energy radiation
particles. Prolonged exposure is extremely
dangerous. Often characterized by their rate of
decay or half-life. The greater the half-life,
the greater the danger 238 Uranium 4,510,000,00
0 yr 14 Carbon 5,730 yr 137 Cesium
30.2 yr 90 Strontium 28.1
yr 131 Iodine 8 days
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1511 Soluble Salts

• Salinization of agricultural soils reduced
  productivity
• Build-up in terminous lakes and estuaries
  Pyramid, Walker, Stillwater, etc.
• What can we do about it?

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1512 Soil Sediment

• Erosion and Deposition Particulate detachment
  and transport by wind and/or water ultimately
  deposit somewhere waterways, storage reservoirs,
  homes, businesses, health hazard
• Eroded lands are less productive, storage
  capacity of water supply reservoirs is reduced,
  water clarity is diminished, lake function is
  degraded
• Also a source of nutrient and pesticide
  transport
• 1513 Summary (On your own)