Benzene: Case Study on Effect of Prop. 65

Wherever there are cars there is benzene, a chemical known to cause cancer in laboratory animals and linked to leukemia in humans as well.

For a decade, federal and state regulators have struggled with the problem of exposure to the chemical, a component of gasoline that is found in vehicle exhaust and the air that most Califo1919838561enough to add between 1,900 and 14,000 cases of cancer over 70 years, according to an estimate by the state Department of Health Services.

Benzene is one of the most ubiquitous of a relatively small number of chemicals that would be initially affected by Proposition 65, the anti-toxics initiative on next Tuesday’s ballot. While its economic importance means that it is hardly typical of the affected543385701illustration of how Proposition 65 would work and what the initiative’s impact might be.

If the ballot measure passes, the governor would have to prepare lists of chemicals that cause cancer or birth defects. A listed chemical would not necessarily be banned, but the initiative would limit the amount businesses could discharge into drinking water sources and require warnings whenever the public is exposed to significant quantities.

The opposing sides in the debate on Proposition 65 have widely divergent views of the impact of the measure on California business and agriculture. They are also at odds on how the initiative would affect more than 200 other chemicals on the measure’s initial list of cancer-causing substances compiled by two respected scientific groups, the National Toxicology Program and the International Agency for Research on Cancer.

Of all the chemicals on this initial list, benzene may well be the most important. It has a great variety of uses, as a solvent and as a chemical building block for a host of other materials. But it also is dangerous; studies have shown that workers exposed to benzene have an increased risk of developing leukemia.

The general public also is exposed to benzene, chiefly from automobile exhaust that contains low but significant levels of the chemical. Motor vehicles account for 93% of the 21,400 tons of benzene spewed into the air in California each year. The levels in California cities are high enough that the Air Resources Board has agreed to a plan that would cut air emissions of benzene in half by the year 2000 in an effort to reduce the risk of cancer.

Proposition 65 would add to the penalties that a business would face for deliberately releasing significant amounts of benzene into sources of drinking water. Benzene contamination of drinking water has been a problem, particularly in Los Angeles County, where a recently completed survey of large water districts found seven contaminated wells.

The initiative would place the burden on businesses to show that the amounts released into water do not add to the risk of cancer, unless the state sets safe amounts by regulation. If the measure passes, most businesses that handle listed chemicals are expected to seek the legal protection that state regulation provides.

But the key issue for benzene and other chemicals would be determination by state agencies or the courts of what level of release constitutes an acceptable risk. (State health officials already have guidelines for permissible levels of benzene in drinking water, but not enforceable standards.)

If the limits are strict, several Proposition 65 opponents say, the effect would be drastic. “You’ll have to alter the formula for gasoline if (benzene) is a significant risk, or you won’t be able to produce it,” said John Hunter, a lobbyist for the California Manufacturers Assn. “I don’t know where the line will be drawn.”

‘Have to Be Strict’

One of the authors of the initiative, Environmental Defense Fund attorney David B. Roe, believes that the limits will have to be strict. Oil companies, he said, “are purveying huge amounts of a known carcinogen.”

At the very least, Roe said, the ballot measure would force gasoline producers to alert the public to the dangers of benzene starting in March, 1988, when the warning requirements for listed chemicals would take effect. “It seems reasonable to me that . . . oil companies give a clear and reasonable warning about benzene,” Roe said.

The opposition argues that even when industry would be allowed to continue to work with suspect chemicals, the measure would require a babble of warnings--so many that their messages would be lost on a confused public.

However, Michael Gagan, manager of the No on 65 campaign, conceded that industry could live with the measure’s warning requirements.

And Hunter, along with other opponents, agrees that only a few of the chemicals on the initial list are likely to cause problems for industry.

Formaldehyde Example

Among those that could prove difficult is formaldehyde, a chemical found in particle board and plywood, as well as in vehicle exhaust.

Residents of mobile homes, which are built with wood products with high levels of formaldehyde, are exposed to significant amounts of the substance, as are people living in houses insulated with a formaldehyde-based foam, according to the latest National Toxicology Program annual report.

“If you have furniture with a veneer over particle board, it probably would have to have a warning,” said Hunter of the California Manufacturers Assn.

However, Proposition 65 author Roe said he is not so sure. “My guess is that the surfaces of table tops are well below (a level that might contribute to cancer). . . . But this requires people to find out.”

Manufacturers of mobile homes might have some special problems. No on 65 campaign material notes that indoor levels in some mobile homes and new houses might be high enough to require warning residents.

Substances in Food

Another cancer-causing group of chemicals on the initial list are the aflatoxins--naturally occurring substances produced by funguses that grow on nuts and grains. Americans consume small amounts of these chemicals daily, in foods such as peanut butter and corn oil. The added risk of cancer is small, but it may be enough to trigger Proposition 65’s warning requirements.

Manufacturers of these products “would have to be able to tell when we are or aren’t being exposed,” Roe said. “A warning label simply gives people a choice.”

However, it is the uncertainty about what new chemicals would be added and the difficulty in proving what levels are safe that has galvanized opponents.

According to Merlin L. Fagan Jr., a lobbyist for the California Farm Bureau Federation, there are only six or seven pesticides still in use in California among the listed chemicals--substances reviewed and found to be cancer-causing by the recognized cancer research bodies.

Many of the pesticides on the initial list already have been banned by state or federal governments, including the insecticide DDT, found to cause cancer in animals. Among the few still permitted are arsenic-containing chemicals used to keep wood from rotting; lindane, a pesticide used to kill fleas and destroy termites, and several chemical weedkillers.

Concern Over Uncertainty

Fagan conceded that the loss of those few chemicals “does not necessarily immediately jeopardize agriculture.” His concern--like that of industry representatives--is over the uncertainty created by the measure, which requires the governor to turn to the “state’s qualified experts” to adopt and amend the list of suspect chemicals.

A number of commonly used industrial chemicals are suspected of causing cancer--including solvents used in paints and dry-cleaning solutions. While these chemicals are not on the lists prepared by the National Toxicology Program or the International Agency for Research on Cancer, scientific advisory panels have recommended that they be added.

Both sides in the debate on Proposition 65 find themselves in the middle of a continuing battle among scientists, industry, environmentalists and regulators about what levels of suspect chemicals are actually safe.

Generally, scientists accept the idea that substances that cause cancer in animals exposed to very high doses are likely to cause cancer in man. But determining a safe level of exposure for humans based on animal experiments is tricky at best. And a number of scientists are uncomfortable with determining just what level is safe enough or what risk is acceptable.

In testimony before the Legislature, Bruce N. Ames, chairman of the biochemistry department at the University of California, Berkeley, argued that the methods widely used to set those levels “may be much too pessimistic.” Ames, who signed the ballot arguments against Proposition 65, argued that there were so many naturally occurring cancer-causing substances in food that the addition of very low levels of pollutants in air or water would be unlikely to have a substantial effect on cancer rates.

Added Risk Small

Even those who sharply disagree with Ames admit that the added risk of cancer from small amounts of any individual chemical is dwarfed by the overall cancer rate. About one out of every four Americans will develop cancer.

Yet many public health experts consider an added risk of one case in 1 million people significant.

The relatively small number of avoidable cancer cases due to pollution “may be all in our power to deal with,” said Ellen Silbergeld, a scientist with the Environmental Defense Fund.

Several scientists interviewed by The Times agreed that existing techniques for estimating cancer risks are necessarily imprecise. “It’s the best that human beings are able to reach by consensus,” said one state toxicologist, who agreed to discuss the issue if he were not identified.

He and others said that there are already widely accepted procedures for estimating cancer risk. However, no such consensus exists for how to estimate the risk of birth defects, miscarriages and sterility.

Another state scientist, who also asked that he not be named, estimated that it would take $3 million a year for three years to develop a consistent policy for identifying chemicals that are likely to cause reproductive effects in humans.

Need to Look Ahead

But supporters of the initiative contend that it is important to move ahead.

“Looking at cancer as the only way that chemicals affect human beings is likely to be highly misleading,” said Silbergeld of the Environmental Defense Fund. She noted that while there is a continuing debate over the safety of small amounts of caffeine and alcohol during pregnancy, most doctors are urging their pregnant patients to avoid both.

Opponents of Proposition 65 contend that the measure would give regulators too little flexibility in weighing the risks of a chemical against its benefits. And by forcing industry to prove that the levels of listed chemicals are safe, the initiative would disrupt California’s economy.

“It’s as if you had to prove you would never be in a car accident before you get in a car,” said the Farm Bureau’s Fagan. “A lot of cars would be left in garages.”

The ballot measure, proponent Roe countered, “exposes some of the hypocrisy of the current system of regulation: If we don’t know, let’s not regulate. This takes a different attitude.”