Water Contamination on the Big Island,
Part 2:   What You Don't Know Will Hurt You

Hawai'i is characterized by volcanic soils and heavy rainfall, making it particularly vulnerable to groundwater contamination. Because groundwater provides a large portion of Hawai'i's population with drinking water, people living in Hawai'i have experienced unusually high exposures to contaminants, especially to chemicals called "endocrine disruptors." These chemicals, found in many commonly used pesticides and herbicides, alter the delicate hormonal balance of the body, leading to diseases, like breast, ovarian and uterine tumors, whose causes are to a large extent hormone-related.

Compared to other US regions, breast cancer's rate of increase in Hawai'i has been unusually high. For example, breast cancer incidence among Japanese women in Hawai'i increased 42% between 1970 and 1985. Rates in other US areas during the same period did not exceed 20%.

Only 30% of these breast cancers can be explained by known risk factors. Increases in breast cancer incidence rates in Hawai'i over the past few decades cannot be attributed solely to improvements in screening and detection. Avoidable environmental factors may contribute to a proportion of the unexplained cases. Emerging evidence on endocrine disruption implies that environmental chemicals may play a role in the development of breast cancer. Agricultural chemicals, including endocrine disruptors, have been used intensively in Hawai'i's island ecosystem over the past 40 years leaching into groundwater, and leading to unusually widespread occupational and general population exposures.

One of the most common chemicals used on the Big Island during the heyday of the sugar industry was atrazine, a herbicide used to control weeds. It was also used on other agricultural crops including, guava and macadamia nuts. Atrazine stays on the surface of the soil for several weeks, but in deeper layers of soil it can remain for months and even years. Atrazine can also break down in the soil. Some of these breakdown products do not bind to the soil, but during heavy rains can move through the soil and contaminate wells, rivers and streams.

It is difficult to say with certainty that atrazine causes breast cancer in humans because there are no published studies that have specifically looked at the rate of breast cancer in women with and without exposure to atrazine. Ironically, nearly all of the studies on agricultural workers exposed to atrazine and cancer risk have been done on men. However, studies performed on laboratory animals clearly suggest that suggest that atrazine is most likely a breast cancer causing agent.

Atrazine may be implicated in other cancers. A higher risk of cancer of the ovaries was observed in one study of Italian women farm workers exposed to atrazine. Atrazine exposure has also been associated with a type of cancer called non-Hodgkin's lymphoma.

Tumors of the pituitary have been observed in studies where atrazine was fed to female rats for long periods of time. A higher number of cancers of the uterus, and of lymphomas and leukemia were observed in one study of female rats that were fed high levels of atrazine.

The agricultural industry has also been responsible for the introduction of other chemicals into the food and water chain. Over the past 40 years in Hawai'i, there has been widespread use of endocrine-disrupting pesticides, including DBCP, DDT, DDE, kepone, heptachlor, chlordane, dieldrin, mirex, lindane and toxaphene. There is a clear synchronicity between that the Big Island's high breast cancer rate and the use of atrazine and other hormone-disrupting agricultural chemicals.

Since 1989 the Hawai'i Department of Health has been issuing the Groundwater Contamination Maps for the State of Hawai`i. These maps identify locations where groundwater contaminants have been detected and confirmed. The entire September 1997 set of groundwater contamination maps for the State of Hawai'i are found in the department of health website listed in the resource section at the end of this article. The maps indicate that atrazine and other agricultural chemicals are found in nearly every well throughout the Big Island in varying concentrations.

Chemical pollution of our water supply isn't the only challenge we face. Tap water in Hawai'i continues to be plagued by basic bacterial contamination problems. Data on compliance with federal health standards, which are supplied to EPA by state authorities, indicate that in 1994-1995, 12,449 people in 8 communities drank water from public water systems containing disease-causing fecal matter. 60,337 people in Hawai'i drank water from suppliers with chronic coliform bacteria, and 43,456 in 13 communities drank from water suppliers that failed to meet EPA standards for adequately filtering and disinfecting tap water.

Based on widespread contamination of Hawai'i tap water by Cryptosporidium, a microbial parasite, the U.S. Centers for Disease Control and the U.S. EPA issued an unprecedented warning that all state residents with compromised immune systems - including cancer and organ transplant patients, and individuals who are HIV positive - should consider boiling their drinking water or drink bottled water.

There is still more. In this country, water suppliers purify drinking water by using sedimentation, filtration, ion exchange and disinfection. Disinfection is achieved primarily through chlorination to kill disease-causing microbes. Chlorine, once the "salvation" of the twentieth century, controls cholera, typhoid fever and other water-borne diseases.

Now, scientists know that chlorine combines easily with other chemicals and naturally occurring organic materials to create new compounds called organochlorines -- potentially .carcinogenic substances. Furthermore, over 96 percent of agricultural chemicals contain chlorine.

You aren’t even safe in the shower. As hot water steams, chemicals evaporate and are inhaled. The amount of chlorine absorbed by your body in a 10-minute shower equals about two gallons of tap water consumption. Taking showers is a health risk, according to research presented in a meeting of the American Chemical Society. Showers -- and to a lesser extent baths -- lead to a greater exposure to toxic chemicals contained in water supplies than does drinking water. The chemicals evaporate out of the water and are inhaled. They can also spread through the house and be inhaled by others.

In the next Healing Island column, I'll discuss the various means by which we may protect ourselves from tap water contaminants.
Attitudes - New Possibilities

Resources:
http://www.Hawai'i.gov/health/eh/eiemdw00.htm
http://www.hi.sierraclub.org/
http://www.aloha.net/~will/Section9.htm
http://www.epa.gov/ow/states/HI/
http://www.ewg.org/pub/home/reports/JustAddWater/JAWStates/JAWHawai'i.html