Anvil 10+10, the insecticide used in the annual West Nile Virus spraying, contains piperonyl butoxide, is listed as a possible human carcinogen by the EPA.  But West Nile carries its own risk. The city must balance the two.

JJ Harrison

Anvil 10+10, the insecticide used in the annual West Nile Virus spraying, contains piperonyl butoxide, is listed as a possible human carcinogen by the EPA. But West Nile carries its own risk. The city must balance the two.

Despite a local law that bans New York City from using pesticides linked to cancer, city agencies apply thousands of pounds of these substances each year.

When Local Law 37 passed in 2005, environmental groups like Beyond Pesticides praised the city for being at the forefront of national efforts to curb pesticides.

And in its annual pesticide reports, the city suggests the legislation has been successful, declaring that as of May 2006, “use of all pesticides classified by the EPA as possible, probable or known human carcinogens ended.”

In November that year, the report continues, the city eliminated pesticides classified as developmental toxins by the State of California – also prohibited under Local Law 37. Finally, EPA Toxicity Category 1 pesticides were prohibited as of November 2005.

But the same reports show that eight years later, a swath of exemptions carved out in the law have freed city agencies and their contractors to continue applying thousands of pounds of these substances each year.

In 2013, the latest year for which data has been released, the city applied 25,000 pounds of solid pesticides that constituted Local Law 37 exemptions, accounting for almost a quarter of the total 111,000 pounds of solid pesticides reported in the latest report. In addition, 1,900 gallons of exempted liquid pesticides were applied, representing over a quarter of total liquids used. Reports dating back to 2007 reveal similar patterns. Despite a trend of decreasing pesticide use by city agencies since reporting began, these prohibited classes do not appear to be declining.

Golf courses a frequent target

Prohibited substances do not include Roundup, the subject of recent intensified scrutiny when earlier this year, the World Health Organization declared Roundup’s active ingredient, glyphosate, to be “probably” carcinogenic to humans. However, the EPA has not designated glyphosate to be carcinogenic nor highly toxic, so its use does not currently require an exemption under Local Law 37. In 2013, the city applied 830 gallons of glyphosate-based products, the majority by the Department of Parks and Recreation

Exempted pesticides do include, however, products containing chlorothalonil, a fungicide listed as a “likely” human carcinogen by the EPA. Chlorothalonil has been found to increase the rate of adenomas and carcinomas in rats and mice.

In 2013, the latest year for which data has been released, the Parks Department reported using 6,150 pounds of chlorothalonil-based pesticides, in line with amounts reported in previous years.

The annual reports do not specify the purpose and location of each application, and the Parks Department did not respond to a request for comment. However, the most common target for fungicides were golf courses, according to the 2013 report.

Indeed, the bulk of the chlorothalonil-containing applications were of Andersons Turf Fungicide with 5.0% Daconil (a brand name for chlorothalonil), which is recommended for use on golf courses, athletic fields, cemeteries and parks. The manufacturer warns consumers, however, not to use the product on home lawns, or turf next to daycares or schools.

Despite being deemed a likely carcinogen, chlorothalonil can be applied on golf courses because under Local Law 37 courses are granted a blanket exemption.

That’s not unusual, says Laura Haight, a former a senior environmental associate at the New York Public Interest Research Group (NYPIRG) who helped advance Local Law 37. She notes that golf courses are routinely exempt from pesticide laws. “They’re incredibly toxic,” she adds.

Also exempt under the law are professional athletic fields, and swimming pools where pesticides are used to “maintain water quality.”

As is often the case with pesticides, although nearly 4,000 pounds of Anderson’s Turf Fungicide were applied, the product’s active ingredient chlorothalonil accounts for only a small proportion—5 percent—of the formulation:. The rest consists of undisclosed “other” ingredients, also known as “inert” ingredients.

Despite being referred to as “inert,” a term the EPA has acknowledged is misleading to consumers, these ingredients can themselves be toxic or possibly carcinogenic, and can enhance the toxicity of the active ingredient. Manufacturers are only legally required to reveal the active ingredients, however.

Health Dept. can grant exemptions

Where a blanket exemption has not been issued, an agency can be cleared to use a pesticide by the Department of Health and Mental Hygiene.

For example, Anvil 10+10, the insecticide used in the annual West Nile Virus spraying, contains piperonyl butoxide, which is listed as a possible human carcinogen by the EPA. Every year since the law came into effect, the Health Department has granted its Office of Vector Surveillance and Control a waiver for “temporary relief from the prohibition on the use of pesticides that may otherwise be prohibited from use on New York City property.”

In an August 8th press release, the No Spray Coalition criticized the Health Department for granting waivers to itself. “No other agency reviews its application. The checks and balances envisioned in Local Law 37 are thus thwarted,” they wrote.

Other pesticides are exempted under city-wide waivers each year. For example, insecticide gels containing fipronil and hydramethylnon both classified as possible human carcinogens by the EPA, are under regular use by NYCHA, which laid down 150 pounds of fipronil-based products across 3,400 applications and 110 pounds of hydramethylnon products across 95 applications.

In the annual waiver letter, Daniel Kass, the Health Department’s deputy commissioner of environmental health, notes that these products are of minimal risk to human health because they can be “used in a targeted manner that limits the likelihood of human exposure.” Likewise, Haight notes that these products are typically enclosed within bait containers.

Fears can be overblown

Possible carcinogens, or even likely carcinogens, might not be cause for concern where exposure is minimal. Anvil, for example, is applied at 0.0034 pounds per acre, Levi Fishman, deputy press secretary at the Health Department, explained in an email earlier this year.

“When properly used, this product poses no significant risks to human health. It degrades rapidly in sunlight, provides little or no residual activity, and does not accumulate in the environment,” he wrote. Nonetheless, the city advises residents to bring children’s toys, outdoor equipment, and clothing indoors before spraying takes place, and to wash anything that has come in contact with Anvil.

Activists like Cathryn Swan of the No Spray coalition aren’t convinced that Anvil degrades as readily as the city assures. The pesticide can, for instance, linger longer in the soil or in areas shaded from sunlight. In soil, the half-life of sumithrin is 1-2 days, meaning it would degrade almost entirely in 5-10 days, but potentially linger much longer in bodies of water, according to the National Pesticide Information Center. No Spray has also expressed concern about potential ecological impacts on bees and aquatic organisms. Local Law 37, however, focuses exclusively on human health impacts..

Even where rates of exposure are greater than anticipated, a possible human carcinogen is not necessarily carcinogenic. The “possible” designation is applied when there is some limited evidence of carcinogenicity. For piperonyl butoxide, lab results have been mixed, with some studies finding cancer-causing at very high doses and others not finding an effect.

However, a pesticide’s risk classification can be a matter of dispute.

Dr. Brian Dementi, formerly a senior toxicologist at the E.P.A., was the lead scientist in charge of evaluating the safety of malathion, the pesticide New York City used before switching to Anvil.

In an independent scientific advisory panel in 2000, Dementi testified that malathion should be classified as a “likely” carcinogen. But in the end, the agency rejected his conclusion, arguing that the insecticide was safe if properly used, and decided to designate malathion as having “suggestive evidence of carcinogenicity”– a lower risk classification.

When the West Nile outbreak first hit New York, and the Health Department was spraying malathion by helicopter, Dementi was conflicted, but ultimately believes the justification for using any given pesticide comes down to a risk-benefit calculation.

“It did indeed bother me,” he says. “But on the other hand, it was preventing encephalitis. One always has to consider the risk assessment… Is there greater risk of not doing it? You’ve always got to discern. It’s a hard thing balancing risk versus benefit.”

Though fewer than 1 percent of those infected develop severe symptoms, West Nile can cause neurological damage and death, according to the Center for Disease Control. Since 1999, there have been 317 cases of symptomatic West Nile infection reported in New York City, 38 of them fatal, according to the Health Department, a rate of under one case per 100,000 people.

Advocate: Notification is key

Despite the Local Law 37 exemptions, Haight, who worked closely with the Health Department on curbing pesticide use during her years at NYPIRG, says she is proud of the law.

“There’s no such thing as a perfect law. All laws are developed with compromises,” she says, adding that she believes the Health Department has acted in good faith to reduce pesticide use and minimize risks. “We worked with a lot of places that passed laws, but no one’s been as vested.”

“The law should be stronger,” says Joel Kupferman, executive director and senior attorney at the New York Environmental Law and Justice Project. Its major weakness, he argues, is that exemptions are granted at the city level. Instead, requests for exemptions should be evaluated at the state or federal level, instead of by the city, Kupferman says. In addition, he believes that agencies offer inadequate, or insufficiently transparent, reporting on adverse effects.

Though New York City and activists might not see eye-to-eye on pesticide risks and classifications, Swan is asking the city to at least better inform residents.

“We’re basically saying you if you are going to do it, at least be giving people proper notification,” she says.

In April, Swan attended meeting of Brooklyn Community Board 7, where a Health Department representative had been invited to talk about the upcoming West Nile Virus spraying. A resident who had signed up for Notify NYC email alerts complained that she sometimes received notice after the spraying had happened. Jeremy Laufer, the district manager, added that 24 hours notice was not enough, and said that the administration relied too much on email, rather than physical notices—a problem for a community where many households don’t have internet access.

Others in attendance wanted to know how dangerous these substances are, whether they were carcinogenic and whether they build up in the environment. The representative, who had only been on the job for three weeks at that point, wasn’t sure of the answers.

The Health Department has not responded to a request for comment about Local Law 37.