DIVING IN CONTAMINATED WATER: THE DANGERS
Many search and rescue divers are unaware of the dangers of diving in polluted water. While some bodies of water don’t appear polluted, they actually can have high levels of biological or chemical contamination. In other environments, divers sometimes mistakenly believe that the water itself will dilute the hazard to a low level. In both settings, such thinking can be fatal.
The same hazardous materials that concern responders on land should concern divers underwater. These hazards include biohazards, toxic chemicals, and radiation. Consider a liquid hazardous material floating in the water around a diver. If the diver is not equipped properly, the material can enter the diver’s mouth through his regulator, get in his eyes through his face mask, or touch his skin through his wet suit.
Toxins that float on top of the water, such as gasoline, also present a serious hazard to the diver. The diver must pass through them to enter or exit the water. Substances that sink in water most likely will collect as pockets of pure chemical substance on the bottom—also an obvious hazard.
Biological pollutants probably are the most common form of hazardous material divers encounter. The three main classes of biological contaminants of concern to divers are baderia—single-celled creatures that exhibit characteristics common to plants and animals, protozoa—singlecelled animals, and viruses—organisms that take over the chemistry of a host cell in living creatures in order to reproduce themselves.
BACTERIA
Fecal coliforms are disease-producing bacteria found in human and animal feces. They are universally present in the water wherever there is raw sewage or inadequate sewage treatment. The maximum safe level of this organism is considered to be 200 organisms per 100 milliliters of water, according to the New York City Department of Health. Swallowing water that contains fecal coliforms can produce severe, disabling diarrhea, which will result in lost time from work.
In the Hudson River in New York City, fecal coliform counts as high as 100 times the maximum level considered safe for human contact have been recorded. In the New River, along the California-Mexico border, fecal coliform counts have been as high as 700,000 per 100 milliliters.
You can expect pollution to be present in the Hudson and New Rivers because of the appearance and smell of their waters. Yet even rivers and streams that appear to he clear and clean may contain high levels of coliforms and other organisms.
Other examples of sites where unacceptable levels of fecal coliforms have been identified include waterways located near cattle ranching operations, such as those in the Tomales Bay drainage in Northern California. Most bodies of water near agricultural areas have similar problems.
Santa Monica Bay off Los Angeles sometimes is closed to water sports due to spills of untreated sewage. This occurs whenever heavy rains fill the storm drains and cause the waste treatment plants to exceed their capacity. In February 1990, eight million gallons of raw sewage spilled into Santa Monica Bay, closing beaches there for several weeks. Similar occurrences are common throughout the United States.
If fecal coliforms are present, it’s a safe bet that there are several other forms of biological pollution present as well. Other dangerous bacteria include Vibrio vulnificus, Aeromonas bydrophila, and those that cause cholera. The current epidemic of cholera in South America is a good example of bacteria that can survive in sea water. Vibrio vulnificus is an extremely potent marine bacteria that also can cause death. It enters the body through the mouth or raw wounds. Aeromonas bydrophila infects open cuts in the body and is commonly found in harbor waters. It was isolated from the nose and throat of scuba-diving scientists after dives in the harbor at Norfolk. Virginia. Aeromonas infections can be fatal if not properly treated.
PROTOZOA
Like bacteria, many protozoa occur as a result of pollution. Eight different species of Acanthamoeba occur in polluted waters. This deadly singlecelled organism causes inflammation of the spinal chord and eventually death.
Giardia lamblia, another protozoan, causes intestinal pain, diarrhea, and high fever. It has been positively identified in stool samples taken from City of New York Fire Department dive team members.
Today most streams in the Sierra Nevada mountains contain Giardia— a result of the great number of campers and backpackers who use the waters for personal hygiene and may transmit the organisms. It is unsafe to drink water from any lake or stream in this area unless it is treated. It is probably equally unsafe to swim or dive in these waters and accidentally swallow any of their contents.
In Florida, protozoa levels in the inland waterways create dangerous conditions for divers. Health officials forbid divers to enter the water unless they are totally encapsulated.
VIRUSES
One of the most commonly known viruses, hepatitis A survives outside the body in both fresh and salt water. Hepatitis A causes an inflamed liver. Like other disease-producing organisms that spread through contact with raw sewage, it can be found in fecal matter.
Most divers wouldn’t consider diving in a vat of untreated sewage; however, that’s exactly what the Houston (TX) Police Department Dive Team had to do several years ago. In 1986, a worker at a sewage treatment plant in Houston fell into a vat of raw sewage and drowned. His body sank to the bottom of the tank. The density of the sewage was similar to thick mud and the temperature in the vat was 80°F. Wearing a special dry suit with an attached diving helmet and gloves, a member of the Houston Dive Team recovered the body without ill effects. This is probably one of the most dramatic contaminated water dives ever made.
OTHER HAZARDS
When emergency services personnel think of hazardous-materials emergencies, they often think of accidental spills of toxic chemicals. However, in many situations, divers also face serious threats from low-level, long-term pollution of waterways.
This long-term pollution continues to occur in waterways as diverse as the harbors of the East Coast, the Mississippi River, and the sparkling waters of San Diego’s Mission Bay. Less obvious threats lurk in the form of pesticides and fertilizers that have drained into irrigation ditches or even water traps on golf courses.
A common scenario search and rescue divers might encounter is a vehicle crashing into a lake or pond. With gasoline and battery acid leaking from the vehicle, the divers must recover the body of the driver. In the past, search and rescue divers have gone into similar incidents without regard for their safety and have suffered chemical burns. Wet suits and other dive gear have been destroyed during these recoveries.
A dramatic example of a toxic “spill” occurred on Earth Day in 1980 when a chemical waste storage site in Elizabeth, New Jersey, exploded. More than 20,000 drums of acids, solvents, pesticides, explosives, and carcinogens were destroyed in the resulting fire. The water used to fight the fire drained into Bayonne Bay.
A third of the firefighters who fought the blaze reported symptoms of illness for up to 10 days after the incident. They complained of skin rashes, nausea, throat irritation, and tingling sensations in the limbs. Meanwhile, the New Jersey Department of Environmental Protection banned commercial fishing downstream of the incident.
Three months after the New Jersey spill, research divers from the National Oceanographic and Atmospheric Administration (NOAA) conducted underwater experiments 22 miles from the site of the explosion. Equipped with full face masks and vulcanized rubber dry suits, they made their dives with no apparent ill effects. Yet at the same time, only a few miles away, two sport divers surfaced, reporting burning sensations around their necks and mouths because they had not taken precautions. Both divers were hospitalized and later released.
San Diego s Mission Bay is a popular water sports location. Yet Mission Bay also has been the site of toxic waste dumping. In 1987 Teledyne Ryan, an electronics firm, was cited by the Environmental Protection Agency tor dumping polychlorinated biphenyls (PCBs) into the bay. PCBs are used in the manufacture of electronic components.
A level of 50 ppm of PCBs results in a hazardous classification for solid waste, according to the EPA. Levels as high as 3,000 ppm were found in a culvert that emptied from Teledyne Ryan’s storm drain into the bay.
Divers from the San Diego Port District conducted training dives in a lagoon where the Teledyne drain emptied into the bay. Levels of PCBs as high as 34 ppm were detected in the waters where the divers trained. PCBs tend to accumulate in the mud on the bottom. The chemicals do not break down for many, many years.
Training dives on small boats were made in the lagoon by Port District divers. As the divers worked in the mud on the bottom, they obviously stirred up the silt. This is a common experience for any diver who has worked underwater in a harbor. The divers wore ordinary wet suits and used sport diving regulators.
Three of the divers on the team developed lymphoma, a form of cancer. One diver has died from the disease. Another diver from the group has developed anemia. While a direct link between the divers’ conditions and the PCBs has not yet been established, the divers have filed lawsuits against Teledyne Ryan.
PCBs released in accidental spills in other parts of the country also pose potentially serious threats to divers. In January 1990, the Avtex Fibers Plant in Virginia spilled close to a million gallons of PCB-contaminated water into the Shenandoah River.
Other hazardous chemicals have been released by industrial firms for many years. In Puget Sound, three different marine regions were declared toxic hazard sites by the EPA in 1988. The two most dramatic were Commencement Bay and Eagle Harbor. They have been listed on the EPA Superfund cleanup list.
Commencement Bay is bordered by refineries, chemical plants, pulp mills, and a defunct copper smelter. Samples of the mud on the bottom have shown unacceptable levels of petrochemicals, copper, lead, zinc, and arsenic. Eagle Harbor has very high levels of PCBs.
Another hazard commonly found in all harbors and marinas is residue from boat-bottom paints. These paints were intended to kill or inhibit the growth of marine life. They have been used on both large and small vessels. However, the same chemicals that discourage marine growth also may be hazardous to humans.
One of the primary components of these antifouling paints is an organotin compound known as tributyltin, more commonly known as TBT. There are 20 TBT compounds; nine are used in boat-bottom paints.
TBT dissolves into fats, giving them the ability to move across the membranes of living cells. This trait is what makes them effective in killing marine organisms such as barnacles. Like PCBs, TBT tends to collect in the silt found on the bottom of harbors.
Almost all the research that has been done on TBT has concentrated on its effect on marine creatures. However, a report by the Brookhaven National Laboratory in Upton, New York, notes that TBT in other applications has toxic effects on the human central nervous system, blood, liver, kidneys, heart, and skin. More alarming, the report notes that while people react to a single acute dose of TBT, repeated subtoxic doses also produce negative reactions. This suggests a cumulative effect, in that low doses keep adding up in a diver’s body after repeated exposures.
Since many rescues and body recoveries take place in harbors and some dive teams train there, these findings should concern divers. A scientist for the EPA has called TBT the most toxic chemical ever deliberately added to the marine environment.
Tributyltin use is restricted in some states and countries. In 1988, the President signed the Organotin Antifouling Paint Control Act. In the same year, the EPA banned the use of TBT on nonaluminum vessels under 82 feet.
High levels of TBT have been found in San Diego Bay, San Francisco Bay, Honolulu Harbor, Long Beach Harbor in California, Narraganset Bay, Thames River in Connecticut, and Mayport, Florida. All of these ports see heavy traffic from Navy ships, and the Navy is a prime user of TBT antifouling paints.
Although tributyltin breaks down in clear waters, it persists much longer in murky harbor waters. The byproducts of TBT decay also are harmful. It may be years after TBT is banned worldwide before it no longer can be detected in the marine environment.
Divers who work around wooden piers and wharfs also should beware of the dangers of creosote. Most wooden pilings are treated with creosote to prevent wood decay. Creosote also discourages marine worms from boring holes in the pilings.
Unprotected divers can receive chemical burns simply by brushing against pilings that are coated with creosote. Firefighters who battle fires under piers face serious danger from creosote-laden smoke.
Hidden chemical dangers can lurk in almost any vehicle that enters the water, be it a car, truck, boat, or airplane. Divers for the FBI have pointed out that water-soluble drugs, such as cocaine, can be released in heavy concentrations in a vehicle accident involving drug dealers. Cocaine can be absorbed through the skin, posing a serious threat to the safety of an unsuspecting and improperly equipped diver.
A program for monitoring the effects of hazardous chemicals on divers engaged in dealing with acute exposures has been developed for the NOAA. Blood, urine, and stool samples are recommended preand postdive when divers expose themselves to specific known chemical toxins. In addition, tests of the divers’ lung capacity are recommended in cases where chemicals are known to affect the divers’ breathing ability.
Radioactive substances are most likely to enter the marine environment through industrial accidents. However, the possibility also exists that someday terrorists may dump radioactive material into a drinking water supply or a harbor. Whatever the source, exposure to radioactive substances is very dangerous. This type of diving should be left to commercial diving firms who have experience dealing with this hazardous material.
Training for contaminated water diving operations is a complex process. There is no single expert on this topic. Instead, it takes the combined talents of many different people to put together a strong training program. Ideally, the staff for a training course in contaminated water diving would include a biologist, a chemist, a hazmat specialist, and a commercial diver.
Few organizations actually train personnel for contaminated water diving. Firefighters trained in both haz-mat techniques and diving make the best candidates for this type of training.
The main skill rescue divers must learn is how to use the specialized diving equipment required for contaminated water operations. This includes dressing the diver, tending the diver, and operating the life support equipment.
With the current emphasis on cleaning up our environment, we can only hope rescue divers will have fewer encounters with contaminated water. For now, the best we can do is to help divers keep informed and be prepared.
Part two of this series focuses on equipment; part three focuses on operations.
