Exam IV Exam IV will be offered on Wed. Dec. 5 in class It will also be offered during the regularly scheduled time Thursday, December 13th Study Guide will be posted this afternoon

A toxic neighbor 90-acre site contaminated with a mix of wood-treating chemicals 90-acre site Gainesville Sun – November, 30th Tests show arsenic and dioxins in the soil at levels exceeding state cleanup standards. Dioxin ½ life in soils: 10 – 30 years

Organic Chemicals

Dioxin PCB DDT Principally carbon, hydrogen 0.2 µg/L 10-31 µg/L (50% Cl) DDT insoluble .2 ug/L = .5g in an olympic sized swimming pool (2,500,000 L) Principally carbon, hydrogen

Improving Solubility Organic Solvents Soap/detergents Hexane Structural similarity between the chemical and the solvent.

Lipids and Solubility Structural similarity between the chemical and the solvent.

Solubility A chemical’s solubility in lipids or organic solvents is inversely proportional to its solubility in water. (Carbon/hydrogen) Carbon/hydrogen water

Consequences Concentration of a chemical up the food chain.

Bio-Accumulation Overall: 120,000 times original concentration Water and phytoplankton to zooplankton: 800 x Zooplankton to fish: 31 x Fish to eagle: 4.8x water to zooplankton: 800x  zooplankton  to fish #1: 31x  fish #1  to fish #2: 1.7x  fish #2 to  gull: 4.8x  overall:  202,368x Overall: 120,000 times original concentration

PCBs Spokane River Nov. 2002 lake trout contained PCBs above the 2000 ng/g level. In fact, 56% of lake trout samples exceeded this tolerance level Carp 3 61.9- 72.8 3400- 7300 66.4 11 2369 269 124 8/17/00 9-BST021.26 Bluestone River at Rt. 643 Falls Mills White Sucker 7 34.5- 43.8 468- 1034 76.4 1.88 61.7 6.12 3.37 Rock Bass 10 16.2-22 80-224 78.9 0.51 49.4 1.98 1.66 Redbreas t Sunfish 11 14.5- 18.1 62-116 78.5 0.88 44.8 2.69 1.69 8/17/00 9-BST029.71 Bluestone 460 Bluefield 15 15-21 62-194 77.6 0.67 4.98 0.65 0.29 Stone Roller 17 13.5- 17.5 36-64 75.2 3.53 7.79 1.79 0.61 12 28.1- 33.9 238- 304 77.4 2.05 29.9 2.37 2.39 Smallmouth bass - 1100-1800 ppb    Round gobies - 200-800 ppb    Zebra mussels - 100 ppb

Toxaphene Biomagnification Seawater 0.0003 ppb Arctic cod muscle 14 - 46 ppb Toxaphene is a manufactured insecticide that contains over 670 Chemicals (ATSDR, 2001).Toxaphene, one of the heaviest used insecticides in the U.S., has been used to control insect pests on crops and livestock and to kill unwanted fish in lakes (ATSDR, 2001). Cumulative world use from 1946 to 1974 was more than 409,000 metric tons (O'Shea, 1999). The United States ceased using toxaphene in 1982, but it is still used in many other countries (O'Shea, 1999). For example, the Virgin Islands and Puerto Rico use it in banana and pineapple cultivation (Burland).Once Toxaphene is added to the environment by human action, it can then enter the air, water and soil. It can enter the air by evaporation, the water through runoff, and the soil by sticking to soil particles (ATSDR, 2001). The most likely route of entry for toxaphene into the environment is evaporation from soils (GPA). Although toxaphene can be in water, it does not dissolve well so it is more likely to be found in air, soil, or sediments underwater (ATSDR, 2001). Once the toxaphene is introduced into the environment it remains there for a long time due to its very slow break down time (ATSDR, 2001). Toxaphene has a half-life as long as twelve years once in the soil (GPA).Toxaphene can be spread through the environment by atmospheric transport and is found in low concentrations in tissues of marine mammals in remote areas were it has never been used, such as the artic (O'Shea, 1999). Narwhal blubber 2440 - 9160 ppb

Non-point source Biomagnified Other Hydrocarbons Chlordane Mirex DDT 1983 1972 Chlordane Mirex DDT Dieldrin Chlordane DDT Urban Runoff Pet wastes, yard debris, paints, vehicle emissions, used or unwanted motor vehicle fluids, car-washing residues, oil and grease from driveways, litter, fertilizers, pesticides and household hazardous chemicals are some urban pollutants that can be carried by water running over land and paved surfaces. This water can flow into storm drains and reach local waterbodies, without being treated in any way. Onsite Sewage Systems Onsite sewage systems which are not properly maintained can cause drainfields to become plugged and cause partially treated wastewater to surface on your lawn and/or flow to nearby waterbodies. Wastewater from improperly constructed or located sewage systems can also pollute ground water. Agriculture Fertilizers, herbicides, pesticides, along with parasites and bacteria from livestock waste, can run off farmland and pollute surface water or seep into the ground and pollute ground water. Livestock movement near and in streams can erode stream banks and destroy fish habitat. Boating Sewage, garbage, dishwater, cleaning and refinishing products and fuel leaks from boats can all damage water quality. Non-point source Biomagnified

Mirex highest levels ever recorded in a living organism. The influence of pollutants such as PCBs, DDT, mirex, and toxaphene is assessed in a population of 500 beluga whales residing in the St. Lawrence River system. This population suffered a dramatic decrease in numbers at the turn of the century, and population numbers continue to slowly decrease. Reasons for this continual decline including biomagnification factors and bioaccummulation are considered. Because they occupy a high level on the food chain, beluga whales accumulate larger quantities of pollutants. Due to the transferance of pollutants through lactation, calves, younger females, and males have higher concentrations than older females. Some of the effects of the pollution are compromised immune systems, reproductive problems, and increased death rates. Pollution is so concentrated in some beluga whale carcasses that they are treated as hazardous waste. Even though belugas have been protected from hunting since the 1970s, their numbers have failed to rebound. Chemical analyses of their blubber have detected PCBs, DDT, chlordane and toxaphene - at some of the highest levels ever recorded in a living organism. highest levels ever recorded in a living organism.

Quantification How can soils help?

An Important Organic Solvent: Octanol C8H18O

The Octanol-Water Partitioning coefficient C8H18O Octanol and water are immiscible Density: 0.824 g/cm3 octanol C8H18O water

Partitioning Carbon/hydrogen Octanol (Carbon/Hydrogen) water C10H20

Add 10 mg chemical 1 L Octanol 1L Water separate chemical Analyze the water phase for the chemical. Difference between initial amount and amount in water = amount in octanol The ratio between the two yields the Kow

Kow = Add 10 mg chemical 1 L Octanol 1L Waterl separate chemical = 999 0.01 mg L Water phase octanol phase

Kow of some Organochlorine Compounds Dioxin 6,000,000 PCBs 2,000,000 DDT 4,000,000 Dieldrin 158,000 Toxaphene 316,000

What does this have to do with soils?

Organic Matter Carbon Hydrogen Oxygen Coiled and convoluted chains of carbon, hydrogen, and oxygen

Organic Matter COOH OH carboxylic enolic C H C Carbon Hydrogen Oxygen

Partitioning/Distribution Organic matter Soil Solution Absorption

Turn 4 pages

Quantifying Partitioning and Absorption in Soils

Quantifying Absorption 1 g Soil added (10% O.M.) 75 mg/L Equilibrium 1 Liter 100 mg/L 25 mg/g Pesticide solution

Distribution Coefficient (mg/g soil) (mg/L solution) Pesticide on soil Pesticide in solution Kd = 75 mg/L Equilibrium 25 mg/g Kd = 25 mg/g 75 mg/L = 0.3 L/g = 300 mL/g Index for a given soil

Two Soils Same Pesticide 75 mg/L 40 mg/L 25 mg/g 60 mg/g Kd (2) = 60 mg/g 40 mg/L Kd (1) = 25 mg/g 75 mg/L Kd (2) = 1.5 L/g Kd (1) = 0.3 L/g = 1500 mL/g = 300 mL/g

Organic Matter and Organic Carbon Retention of organic chemicals is strongly correlated with O.C. content Organic matter = 40 - 60% carbon approximately 50% organic carbon

Organic Carbon Distribution Coefficient Kd Koc= Fraction o.c. 75 mg/L 25 mg/g Kd (1) = 3 L/g 10% o.c. Koc (1) = 0.3 = 3 L/g 0.1 40 mg/L 60 mg/g Kd (2) = 1.5 L/g 50% o.c. Koc (2) = 1.5 = 3 L/g 0.5 = 3000 mL/g = 3000 mL/g

Koc of some Organochlorine Compounds PCBs 2,000,000 DDT 4,000,000 Dieldrin 158,000 Toxaphene 316,000

Modern Pesticides Atrazine Solubility = 30 mg/L Carbaryl napthalene Solubility = 32 mg/L C C C C

Koc = 2 – 6000 mL/g Dicamba = 2 Malathion = 1800 Chlorpyrophos = 6070 Practical Range for Some Modern Pesticides Koc = 2 – 6000 mL/g Dicamba = 2 Malathion = 1800 Chlorpyrophos = 6070 http://soillab.ifas.ufl.edu/cmis/

http://soillab.ifas.ufl.edu/cmis/

Summary Many organic compound are non-polar Non-polar compounds are weakly soluble in water Non-polar compounds are soluble in organic solvents. Organic matter can behave like an organic solvent Kow describes the distribution of a chemical between the organic solvent, octanol, and the soil solution. Koc describes the distribution of a chemical between soil organic carbon and the soil solution. Koc will impact the movement and distribution of organic chemicals in soils. Organic chemicals degrade. The ½ life is an indicator of the chemicals relative persistence.