SECTION: REAL ESTATE;Pg. H-13

LENGTH: 1503 words

HEADLINE: Use of popular insecticide being phased out

BYLINE: VINCENT LAZANEO; Vincent Lazaneo is a farm adviser with the University of California Cooperative Extension Service.

BODY:
Dursban and most other products containing the insecticide chlorpyifos have begun to disappear from shelves at local garden centers and will no longer be sold for home and garden use at retail stores within 18 months.

Nearly all indoor and outdoor residential uses will be eliminated and phased out in order to provide an additional measure of protection for children and the environment under a recent agreement between manufacturers of the insecticide and the U.S. Environmental Protection Agency.

Within a few years this action and other provisions of the agreement are expected to reduce by half the annual application of chlorpyrifos in the United States, estimated to be over 20 million pounds.

This ban, however, will not leave residents defenseless against an onslaught of home and yard pests. There will still be a large array of other insect-killing products for consumers to buy and many nonchemical methods which they can use to combat troublesome pests in and around homes. Widely used

First registered in 1965, chlorpyrifos is one of the most widely used organophosphate insecticides in the United States. Manufacturers currently produce more than 850 products containing the insecticide.

An estimated 20 million to 24 million pounds are applied annually with about the same amount used in agriculture and in nonagricultural settings. About half of nonagricultural use is for termite control with the remainder used to control other pests around homes and other structures and outdoors on lawns and landscape plantings.

Based on a review of chlorpyrifos, the EPA determined that the insecticide as currently used does not provide an adequate margin of protection for children required by the 1996 Food Quality Protection Act, which established a new, more stringent safety standard for most pesticides.

The EPA and chlorpyrifos manufacturers signed an agreement June 5 that will ban and phase out many uses of the organophosphate insecticide by 2005.

This agreement provides greater protection for children by eliminating or reducing the most important sources of exposure of children to the insecticide. It also significantly lowers allowable residues (tolerances) on certain crops including fruits and vegetables regularly eaten by children.

The EPA is taking the fastest action possible to remove household products containing chlorpyrifos from the market. According to EPA Administrator Carol M. Browner, this action will:

[] Stop production by the end of the year and eliminate all home and garden uses.

[] Eliminate all termite-control uses in existing homes by the end of the year.

[] Eliminate use of chlorpyrifos in all sensitive areas, such as schools, day-care facilities, parks, hospitals, nursing homes and malls by the end of the year.

[] Eliminate or dramatically lower pesticide residues on several foods by next growing season.

[] Eliminate the use of chlorpyrifos as a termiticide for new-home and building construction by the end of 2004.

Retail businesses are allowed to sell chlorpyrifos through the end of 2001. But products containing the insecticide have already been voluntarily taken off the shelves at Walter Andersen nurseries in San Diego and Poway.

Vice President and General Manager Ken Andersen said the action was prompted by concern for the safety of customers, employees and the environment.

The nursery's actions may challenge other retailers to do likewise although, according to the EPA, chlorpyrifos do not pose an immediate or short-term health risk if products are used according to label directions.

Children at risk

Chlorpyrifos belongs to the class of insecticides known as organophosphates. Insects absorb the chemical through direct contact or by eating the residue on treated plants. The chemicals kill them by interfering with an enzyme necessary for normal nerve transmission.

Organophosphate pesticides also are potentially toxic to humans. However, since we are much larger than insects, it would take a much bigger dose to be lethal or harm our nervous system.

People can absorb pesticides through their skin and by ingestion or inhalation. Whether a person develops symptoms of pesticide poisoning depends on a chemical's toxicity, how much of it is present, and the length and frequency of exposure. Other factors such as genetic makeup, general health and age also play a role.

Infants and children may be especially sensitive to health risks posed by pesticides for several reasons. Their internal organs are still developing, and in relation to their body weight, they eat and drink more than adults, possibly increasing their exposure to pesticides. Additional exposure could come from playing on floors and lawns and putting objects in their mouths.

Pesticides may harm a developing child by blocking the absorption of important nutrients. They also may cause harm if a child's excretory system is not fully developed, preventing pesticides from being removed quickly or completely from the body.

There are also critical periods in human development when exposure to a toxin can permanently alter the way an individual's biological system operates.

For these reasons, and as specifically required by the 1996 Food Quality Protection Act, the EPA carefully evaluates children's exposure to pesticide residues in and on food. And organophosphate pesticides, including chlorpyrifos, that affect the functioning of the nervous system are among the EPA's highest priority for review.

Consumer options

Current uses of chlorpyrifos, which could potentially expose children to the organophosphate insecticide, will be eliminated and phased out within a few years. Those that pose the most immediate risk will be canceled first, including home lawn, indoor crack and crevice treatment, and full house post-construction termite treatment. Sales for these and most other residential uses will end Dec. 31, 2001.

Consumers will continue to have a selection of older but still popular broad-spectrum pest control products. Organophosphate insecticides which customers may substitute for chlorpyrifos include: Acephate (Orthene), Diazinon (Spectracide), Dimethoate (Cygon), Disulfoton (Di-Syston), and Malathion.

Other broad-spectrum products which may substitute are the carbamate insecticide Carbaryl (Sevin) and the Organochloride insecticide Endosulfan (Thiodan).

These pesticides have been in use for many years but they may not be around much longer. The EPA is reviewing all older pesticides to ensure they meet the tough new safety standards and it is very likely that most of the pesticides listed above will not be sold for home use by the end of this decade.

Overuse of these pesticides has increased pest resistance and withdrawing the products would not be a great loss. They also kill many beneficial insects as well as pests and harm the environment when they wash into streams and other bodies of water.

Fortunately, a new generation of pest control products has already begun to appear. Organophosphate insecticides are being replaced by another class of synthetic pyrethrin compounds called pyrethroids.

Many more environmentally friendly pest control products also are now available, including new, more effective ant baits, insecticidal soap, horticultural oil, insect growth regulators such as neem oil, and biological pest control products like the caterpillar-killing bacteria bacillus thuringiensis and insect killing nematodes, as well as beneficial insect predators and parasites.

Some examples of the new generation of pest control products are listed in the accompanying table. Most of these products are available from local nurseries or garden centers. A few also are available from mail-order companies.

Some products control a single pest such as ants and others control a wide range of pests. The table indicates which products will control ants, aphids, fleas, lawn insects and spiders. These pests account for most urban applications of Dursban and Diazinon by consumers in a survey conducted by the Integrated Pest Management program at UC Davis.

When pests appear in a home or yard, it's best to try nonchemical control methods first before resorting to a pesticide. When chemical treatment is required, select the least toxic product.

Information on nonchemical and least toxic methods of controlling 80 common pests is provided in the University of California Pest Notes. People with Internet access can find Pest Notes at http://www.ipm.ucdavis.edu/ PMG/selectnewpest.home.html.

Print copies of UC Pest Notes on ants, aphids, fleas, lawn insects and spiders also can be obtained by calling the UC Master Gardener hotline (858) 694-2860, which is staffed by volunteers from 9 a.m. to 3 p.m. on weekdays.

Vincent Lazaneo is a farm adviser with the University of California Cooperative Extension Service. Send your questions to him in care of the Home section, The San Diego Union-Tribune, P.O. Box 120191, San Diego, CA 92112-0191.



GRAPHIC: 1 CHART; UNION-TRIBUNE | SOURCE: UC Cooperative Extension; Dursban substitute products (H-21)

LOAD-DATE: August 9, 2002