Living Downstream: A Scientist's Personal Investigation of Cancer and the Environment

Hubbard Brook Experimental Forest in the White Mountains of New Hampshire provides research on the cycling of nutrients through a living community. What we know about nitrogen, phosphorus, and calcium emerges out of scientific studies completed in this area. Researchers found that fallen leaves and soil in the area contained traces of DDT and PCBs—but none of these chemicals had been used or produced in the area where the chemicals were found. Traces increased with elevation, suggesting atmospheric deposition. Toxins may have been delivered by storm systems that swept over industrialized areas, landfills, or farms. Chemicals from these areas have been found in tree bark all over the world, including the Arctic. The largest amount of toxins is in areas furthest from the source—a phenomenon known as Arctic Paradox, which occurs through a process known as global distillation. Not all dangers from carcinogens come from air; some come from food. Some of the contaminants we encounter come from distant farms and industries.

More than a third of all toxic chemicals released by industry in 2007 went into the air. Despite the 1970 Clean Air Act, 60% of Americans live in areas with unhealthy air. How much airborne carcinogens contribute to cancer is still in question, as the fluidity of air and wind makes it difficult to determine. Some air chemicals aren’t monitored for fine and ultrafine particles, and some chemicals in the air mix with other chemicals to form different or new carcinogens. Ozone is most notorious. Ozone itself isn’t a carcinogen, but it hinders the body’s ability to filter carcinogens. The National Air Toxics Assessment in 2009 suggested links to cancer through contaminated air.

Lung cancer kills quickly and is a leading cancer in the US. Though smoking is a leading cause of the cancer, its incidence among nonsmokers remains a mystery. Lung cancer is more prevalent in urban areas, and studies suggest higher cancer and mortality rates in areas where airborne particles are denser. Burning of fossil fuels and exposure to traffic exhaust at an early age are under scrutiny. Exposure to exhaust produced breast and bladder cancer at rates similar to previously identified substances.

In the 19th century, many physicians believed that infectious disease was brought on by bad air. The miasma theory dictated that air became corrupted when it passed over sewage, decay, swamps, etc. This theory led to closed sewers, clean drinking water, and deep burial of the dead. Increases in child asthma and lung cancer in city residents is a telling sign that bad air contributes to disease.

Steingraber describes mussel gatherers showing off their captures on the Illinois River in a picture from the early 1900s. They’d sell their catches to one of many button factories along the river. By 1948, the last factory had closed; mussels had disappeared from the area, and plastic was used for shirt buttons. Diving ducks also began disappearing. Researchers blame the disappearance of scaups and fingernail clams on organochlorine contamination. The arrival of herbicides wiped out other species of ducks, and wild vegetation in Peoria Lake disappeared by the 1950s, as did the birds that fed on it.

By the turn of the 20th century, over 2,000 commercial fishers worked on the Illinois River and sold their catches to markets as far away as Boston. The river was regarded as the most productive in North America. Chicago Sanitary & Ship Canal, which connected Lake Michigan to the Illinois River, contributed Chicago’s wastewater to the river. The river rose, flooded areas stayed flooded, and the river became a sewage canal for industry. The Clean Water Act of 1972 brought improvements to the river. In the Upper Illinois River, however, fishery warnings encourage fishermen not to eat fish from the river. More than 350 hazardous waste spills were reported between 1974 and 1989—and the lack of bottom-feeding life suggests that the spills are still occurring. Since 1908, 20 species of fish have disappeared.

The Safe Drinking Water Act of 1974 placed regulations on drinking water. The act allows the EPA to set the allowable toxins in drinking water, and each chemical has a different allowance. However, according to recent research, 10% of the nation’s drinking water is out of compliance with EPA regulations. Regulations and limits involve a compromise between human health and economics: Bans consider the cost and the technology available to control contaminants. However, individual maximum allowances don’t consider the hazardous potential of contaminants when they mix with each other and create more toxic substances. Some toxins naturally found in drinking water aren’t considered, and some of the limits were set based on other health concerns rather than cancer specifically. Some contaminant levels are based on annual averages of recordings, which is a problem in the Midwest, where levels are significantly higher during the spring planting. Our bodies don’t function on averages, and researchers believe that even minute exposure to toxins at an early age can increase the risk of cancer.

A 1993 report on groundwater quality released in Steingraber’s hometown revealed contaminated drinking water wells located near the river and close to a sewage plant, industrial sites, and underground storage tanks. Kenneth Cantor, an environmental epidemiologist and senior scientist at the National Cancer Institute, notes that the link between groundwater and cancer is difficult to summarize because of too many possible combinations of chemicals in the water over unknown periods of time. Tests at Camp Lejeune, a US Marine Corps Base Camp in North Carolina, aren’t helpful because of the time that passed and the number of people who moved away. These tests resulted in conflicting reports and many inconclusive results despite testing some of the population that were near the drinking water and developed cancer. Studies like these call for action and further research. Studies of superfund sites in Pennsylvania and New Jersey and abroad have had some success.

Chlorine added to public drinking water to combat waterborne illnesses has been linked to cancers of the bladder, colon, and rectum. The poison is produced when chlorine mixes with organic materials in the water. Alternative methods to treating water have been called for, and money is being spent on looking at water disinfection byproducts. We need a new urgency and creative approach to water disinfecting methods, and keeping carbon-based contaminants out of drinking water is essential.

Studies of the Sankoty Aquifer in Pekin failed to explain how the contamination began and progressed, though flooding and rising river waters may be to blame. Pekin’s treatment of groundwater, however, became a model to the state and has promoted positive conversation and concern for water resources in the area. Nevertheless, sewer runoff into certain bodies of water and rain still leads to trace amounts of contamination in the Pekin water supply. In April 2009, the US Geological Survey reported increases in contaminants in both local and national water supplies.

The Illinois Retail Rate Law required electrical power companies to purchase, at a retail rate, the electricity generated by trash-burning incinerators. The companies were eligible for tax credits to make up for lost profits, and garbage incinerators soon became the most heavily subsidized development project in Illinois history. The incinerators used in medical and household wastes became expensive to operate and released dioxin, a known carcinogen dangerous at low levels, into the air. Dioxin is known to affect the reproductive and immune systems as well as infant development and was added to the list of chemicals to globally abolish.

Incinerators have had a rocky past. Popular in the 1960s, they began to lose favor because of their contribution to air pollution. Landfills quickly became the way to eliminate waste but became a contributor to groundwater pollution. In the 1980s and ’90s, incinerators reemerged, citing new technology that allowed control of the amount of toxins, such as dioxin, they released into the air. However, the expenses associated with incinerators led many cities to abandon them. Now rebranded as “renewable” energy, incinerators are making a comeback with even newer technology. However, the disposal of ashes contributes to additional hazardous materials that can’t be destroyed, while the airborne toxins that the incinerators still release doesn’t disappear.

Steingraber talks about traveling to visit Dorothy Anderson, a pediatrician and the president of the Mason County Board of Public Health, to discuss an incinerator being proposed for a site 80 miles from her home, near her brother’s farm. The town is torn apart by promises of jobs, economic gain, new schools, and libraries.

Dioxin is difficult and expensive to study because of its high level of toxicity at low levels, but it has been linked to developmental deformities of the mammary glands in lab rats, impacting milk production and leading to the death of offspring. Although difficult to trace, studies of industrial workers and individuals exposed to chemical spills have suggested a link between dioxin and cancer incidence, but no one type of cancer stood out, though studies suggest a higher incidence of breast cancer in areas of higher dioxin contamination. Meanwhile, zero waste programs seek to end our dependency on incinerators and landfills.