Information about Dioxin and the Tittabawassee River Flood Plain
From Brochure developed by Michigan Departments of Community Health, Agriculture, Environmental Quality, and Public Heath Departments serving Midland and Saginaw Counties 2002. The actual brochure was last located at http://www.deq.state.mi.us/documents/deq-erd-triver-pr2-river-brochure.doc
What are dioxins, where do they come from & are they harmful?
Dioxin is the name given to a group of chemicals that are formed as unwanted by-products of industrial manufacturing and burning activities. The major sources of dioxins include chemical and pesticide manufacture, burning household trash, forest fires, and burning of industrial and medical waste products.
The harmful effects of dioxins are not fully known but some dioxins are considered much less harmful than others. The primary concern is their potential to cause ill effects in people based on daily exposures over a long period of time (many years). Because this potential varies with each form of dioxin, scientists have agreed to report dioxin levels by combining dioxin forms and converting them to an "equivalent" of that form considered most harmful. Thus, dioxin levels are usually reported as the total "toxic equivalent" (TEQ) concentration of the dioxins.
Soil & Sediment Samples
Why are dioxins a concern in the Tittabawassee River flood plain?
The Michigan Department of Environmental Quality (MDEQ) has found higher than normal levels of dioxins in soil and sediment samples taken from the flood plain of the Tittabawassee River. Samples were taken from some private property and from public parks including the Chippewa Nature Center, West Michigan Park, Imerman Park, Freeland Festival Park, the Caldwell Boat Launch, and Emerson Park. The levels of dioxins found at some of these locations exceed the Centers for Disease Control (CDC) and the U.S. Agency for Toxic Substances and Disease Registry (ATSDR) action level of 1,000 parts per trillion (ppt) for dioxin. Similar levels of dioxins may be found in other areas of the flood plain of the Tittabawassee River downstream of Midland. The MDEQ is taking more samples in the flood plain to determine the extent of contamination. Soil samples taken from areas outside the flood plain were at normal background levels.
What health effects could be caused by dioxins in the flood plain?
People living in the flood plain could be exposed to dioxins in the soil and sediments. In animal studies, low-level exposure to dioxins over long periods of time caused cancer, liver damage, and hormone changes. In some studies, dioxin exposure also decreased the ability to fight infection and caused reproductive damage, miscarriages, and birth defects. Skeleton and kidney defects, lowered immune responses, and effects on the development of the brain and the nervous system were among the birth defects seen.
Some studies suggest that people exposed to low levels of dioxins over many years may show the same health effects seen in animal studies. More information is needed before it can be determined if people can be harmed by exposure to the levels of dioxins found in the Tittabawassee River flood plain.
Are children more sensitive to dioxins?
Fetuses, infants, and children may be especially sensitive to dioxin because they are growing and developing rapidly. However, information on the effects of dioxin in children is limited. Although breast milk may be a source of dioxin exposure for nursing infants, overwhelming evidence supports the greater health benefits of breastfeeding in spite of any dioxins present.
Has the health of people living in the flood plain been affected by dioxin?
There is no known evidence of any health effects or illnesses that may have occurred in people as a result of exposure to dioxins in the flood plain. Health officials at the federal, state, and local level are discussing studies that could provide this information. Residents in the flood plain will be made aware of plans to conduct health studies and will be provided an opportunity to comment on the plans at future public meetings.
How can I be exposed to dioxins?
People are mainly exposed to dioxins through their diet. People who live where dioxin levels in soil and sediment are at normal background levels, get most of their exposure to dioxin from the food they eat. However, people who live where dioxin levels in soil and sediment are higher may get a larger percentage of dioxin from other exposures. People who eat eggs, milk, chickens, beef, or other products from animals raised on contaminated flood plain soils may take in more dioxin than the average person. People who eat fish from lakes or rivers where dioxin levels in the sediments are higher, may also take in more dioxin than the average person. Please note, there is no known commercial production of these foods from the Tittabawassee River flood plain area.
Can I get tested for dioxins?
Special tests are available to measure dioxin levels in body fat, blood, and breast milk, but these tests are very expensive and are not routinely available to the public.
How can I lessen my exposure to dioxins in my diet?
Dioxins accumulate in the fatty tissues of animals. Foods such as eggs, milk, chicken, beef, or other animal products that contain animal fats may also contain dioxins. Therefore, maintaining a diet lower in fat as recommended by the USDA and FDA is the first step in reducing exposure to dioxin.
Eggs, milk, chicken, beef, or other products from animals raised in the flood plain of the Tittabawassee River could contain high levels of dioxins. Animals that feed or graze directly on soil also eat soil particles as they feed. If the soil is contaminated, the animals take in dioxins that are then passed to eggs, milk, or meat. Until the health risks can be better assessed, people should not eat or sell food products from animals raised or fed directly on soils in the flood plain of the Tittabawassee River downstream of Midland.
Plants take up only a small amount of dioxins present in the soil. However, fruits or vegetables can be contaminated if dust or soil that contains dioxins is deposited on them. All fruits and vegetables, regardless of their source, should be washed and pared or peeled to reduce the chance of exposure to bacteria and chemicals including dioxins.
The MDCH has issued fish advisories for the Tittabawassee River below the city of Midland. The MDCH recommends that you do not eat carp, catfish, or white bass taken from this stretch of the river. The MDCH further recommends that most people eat only one meal per week of smallmouth bass. Children and women of childbearing age should not eat smallmouth bass. For all other species of fish in the Tittabawassee River, the MDCH recommends that children and women of childbearing age eat only one meal per month. The rest of the population is advised to eat only one meal of these fish per week. Fishing advisories are available free by calling 1-800-648-6942.
How can I limit my exposure to dioxins in soil and sediments?
There are some common sense steps you can take to limit your exposure to the dioxins found in the flood plain. If you have been playing or working in soil that could be contaminated, wash your skin to remove any dirt. Thorough hand washing is especially important before eating. Children playing outside should be prevented from putting toys or other dirty objects in their mouths. Clean fill dirt can be added over contaminated dirt in gardens, on lawns, and in play areas if dioxin contamination is known or suspected. However, if the area is flooded after clean fill is added, the surface soil could be recontaminated. Care should be taken not to disturb the layer of clean soil covering the contaminated soil. Because they may be especially sensitive to dioxins, children should not play in soil or sediment that is known to contain elevated levels of dioxins.
What is being done to prevent movement of contaminated soil?
The MDEQ issues permits for dredging or other soil movement. These permits are issued throughout the State of Michigan for certain flood plain projects. As a part of this permit review and issuance process, dioxin analyses will be required for soils in the flood plain of the Tittabawassee River if the soils are proposed to be moved from the flood plain to any property other than a municipal solid waste landfill. Dioxin analysis will also be required for the dredging of Tittabawassee and Saginaw River sediments. Dioxin analyses will not be required as a part of a proposed permitted activity if the soils are being moved on-site within the flood plain or to a municipal solid waste landfill. Although an MDEQ permit is not required for all soil movement activities that might occur within flood plain areas, other regulations may apply. Therefore, the MDEQ recommends that owners of property within the flood plain of the Tittabawassee River refrain from any activity on the property that would result in the movement of flood plain soil to areas outside of the flood plain, both on or outside of their property boundary unless the soil is being moved to a licensed solid waste landfill or is properly analyzed prior to decisions about where it is to be moved.
Is there a test to tell if soil on my property is contaminated?
Soil tests for dioxins are expensive and not all laboratories can reliably measure dioxins in soil. If a company that is offering soil testing for dioxins contacts you, contact one of the agencies listed below for guidance.