Pfiesteria in our waterways: is this the example we have been waitingfor?

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Pfiesteria in our waterways: is this the example we have been waitingfor?

(Pfiesteria piscicida)(Out of the In-Basket)(Column)

Journal of Environmental Health

1-11-1998

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When public health professionals talk about prevention, the purpose is

often to demonstrate the value of some type of intervention intended to

prevent disease or injury. We estimate how many lives would be saved or how

many illnesses prevented as a result of the intervention. Such estimates,

however, are always just a best guess - usually based on a worst-case

scenario. Unfortunately, that approach does not often convince elected

officials that such a risk could become reality, so resources go to the

treatment of more visible and recognizable problems. Often, treatment

instead of prevention continues to be the direction of choice.

Usually the worst-case scenario does not come true. Relative to

environmental issues, there is always a more compelling reason to allow more

development, increase the discharge of chemicals or microbes into the

environment, or allow a variance from the letter of the law. Well, experts

in North Carolina might suggest that the worst-case scenario has become a

reality. That reality is the microorganism Pfiesteria that is ravaging the

fish population in North Carolina, land, and Virginia rivers. This

outbreak may carry a message that deserves our attention; it may be a

wake-up call that should not be ignored.

Pfiesteria piscicida is a one-celled dynoflagellate that secretes two

toxins. Since it was discovered in 1991, it has killed hundreds of millions

of fish and closed fishing areas and shellfish beds. It is thought by many

that toxic algal blooms are triggered by nutrient- rich sewage effluent,

farm runoff, and factory waste-water flowing into bays and estuaries. U.S.

EPA has reported a strong correlation between high nutrient levels,

Pfiesteria, and algal blooms. As fish swim by the organism, it attacks with

its twin flagella and releases a toxin that is deadly to the fish. The

neurotoxin is also thought to be the cause of severe neurological symptoms

in fisherman. About 100 cases in fishermen have been identified in North

Carolina.

There are still uncertainties about the toxicity profiles of the toxins

emitted from Pfiesteria and the role of nutrient-rich water in the

organism's ability to thrive. The microbe is, however, widely acknowledged

to be the source of significant risk to fish and possibly to human beings.

While research into the dynamics of Pfiesteria and the extent of the

potential problem is under way, environmental health professionals should

also be considering the implications for other waterways in the United

States.

There are 127 ecologically and commercially important bays and estuaries in

the United States. Furthermore, 75 percent of the population lives within 50

miles of the Great lakes or a coastline. What is the implication of a

potential environmental disaster in the rivers associated with the bays,

estuaries, and coastlines in terms of ecological balance, meeting fish

consumption demand, and the economics of the fishing industry?

Environmentalists have suggested that inadequate attention has been paid to

the pollution reduction features o f the Clean Water Act. Others have called

for more stringent regulation of the poultry- or hog-raising industries to

prevent the runoff of nutrients from such sites into waterways. Sources of

nutrients also include residential and business development whose runoff

contains fertilizers, pesticides, and other nitrogen- and

phosphate-containing substances. Although commercial poultry and hog farming

may be the easiest target, land development in general may deserve more

attention. In addition, the Pfiesteria problem may be just a symptom of a

larger problem. The effects of environmental pollution on natural resources

may extend beyond Pfiesteria and our fisheries.

The assessment of environmental risks associated with various development

and redevelopment strategies does not always receive adequate attention.

Planning agencies may or may not refer new development to local

environmental health professionals for comment. If input is requested,

environmental health professionals are not likely to have information

adequate to address some of the most important issues. For example, where

are the vulnerable areas in which pollution may influence air, water, or

soil quality? What is the spatial relationship between potential sources of

chemical contamination and vulnerable areas ? How will development change

the character and flow of stormwater runoff? What risk does the use of

on-site wastewater disposal present to shallow groundwater that may be a

drinking-water source? What other areas of vulnerability exist that threaten

air, land, water, or human and ecological health? What other sources of

nutrient loading may pose a particular risk (e.g., golf courses built in

flood plains)? Are the risks short term or long term?

In many fast-growing areas of the country,, new development pressures seem

to supersede concerns about risks to public health and the environment.

Citizens often complain that many elected officials lack the political will

to resist the overtures of developers who claim to bring prosperity to the

community. Also, officials typically cannot ask probing questions or

challenge the plans of developers because they do not have the benefit of

data from a sound, science-based assessment of environmental risks. We often

speculate that there are risks, but frequently we cannot make a compelling

case to demonstrate that risk factors define the probability of a negative

health or environmental effect. If we had information that better

characterized potential risks, concerns about the conflict between new or

existing development and ecological or human health risks could be better

evaluated.

Even without the results of a formal assessment, there is a role for

environmental health professionals in promoting community protection. For

example, we can advocate for a policy of pollution prevention as the

environmental management tool of first choice. Strategies such as energy

conservation, turf management, water use reduction, and source reduction can

be effective in reducing the potential negative effects of development on

health and the environment.

Regulatory options must also be considered but should not be viewed as a

panacea. Strengthening environmental regulation to address the Pfiesteria

problem may be necessary in the short term. Establishing more stringent

discharge limits requiring end-of-the-pipe treatment may, however, not

represent the most effective long-term approach to preventing the threat

such organisms pose to human beings and the environment. Likewise, placing a

moratorium on development is not the only solution. Bringing sound

information into the land use decision- making process at the local level

may present a more effective long- term strategy for coping with threats

such as that presented by Pfiesteria. Through long-range planning, areas

that are vulnerable to environmental contamination can be identified and

included in the community master plan. Developers can then be challenged to

demonstrate how their plans address the risks identified. Together with

effective environmental regulation, this approach could provide an effective

overall strategy for protecting public health and the environment.

Elected officials often ask for visible evidence of the need to allocate

more resources to public health or to make the tough decisions to restrict,

downsize, or revise land use plans. Public health is often in the unenviable

position of demonstrating success through the absence of illness or death.

The question is whether lives were saved or prolonged because of a

prevention strategy or because there was not a problem in the first place.

The Pfiesteria threat may provide environmental health professionals with an

opportunity to demonstrate what can happen when ecological balance is upset

and pollution is not adequately controlled. Instead of rejoicing that

Pfiesteria does not present a risk to your community, take the opportunity

offered by a " teachable moment. " Now is the time to find a local analogy -

to point to a site where the byproducts of development meet valued

environmental resources and pose a significant risk to the community and the

environment.

National Environmental Health Association

Wiant, J., Pfiesteria in our waterways: is this the example we have

been waiting for? (Pfiesteria piscicida)(Out of the In-Basket)(Column).,

Vol. 60, Journal of Environmental Health, 01-11-1998, pp 28(2).