West Nile virus: legal responses that further environmental health.

Introduction

From 1999 to the first half of the present decade, West Nile virus (WNV) has spread throughout the United States. WNV infections among humans increased annually from 1999 to 2003, when they reached a peak of 9,862 reported cases, followed by 2,470 reported cases in 2004 (Centers for Disease Control and Prevention [CDC], 2004). The number of actual cases over the last five years is likely far higher. For vulnerable individuals (e.g., elderly persons or those with suppressed immune systems), WNV infections can be debilitating or fatal. CDC confirms that at least 88 people died from the disease in 2004 (CDC, 2004). For these reasons, federal, state, and local public health and environmental agencies have worked extensively to limit the spread of the virus through mosquitoes to birds, horses, and humans.

As with many threats to the public's health, law is an essential tool for improving public health outcomes. In response to WNV, the legal community (principally state and local legislators) has introduced statutory and regulatory laws often focused on environmental interventions. State legislative proposals authorize state and local departments of health, environment, sanitation, and transportation to 1) conduct mosquito abatement programs under existing laws, 2) craft mosquito abatement measures specifically in response to WNV, 3) abate public nuisances in the environment that foster the spread of WNV, and 4) establish public awareness and education campaigns about WNV. Collectively, these legal interventions have helped control WNV among populations.

Public and legal controversy, however, has surrounded some legal responses to WNV that focus on enhanced mosquito abatement efforts. The widespread spraying of pesticides in New York City without advance notice in the summers of 1999 and 2000, for example, was challenged by environmentalists concerned about the effects of these chemicals on human health and the environment. Opposition groups aligned to sue New York City to stop pesticide spraying. Public health officials strongly asserted the need to spray widely for mosquitoes to eliminate the threat of WNV. Environmentalists feared that the widespread spraying of insecticides posed a much greater threat to the public's health than WNV itself. This case study, based on the experiences of Wilfredo Lopez, J.D., general counsel of the New York City Department of Health, and detailed further below, highlights prominent legal and public health issues at play in the spread of WNV. Resolving these issues is difficult when mosquito abatement measures involving the spraying of insecticides are effective but may also negatively affect environmental and human health.

West Nile Virus in the United States

WNV is an arbovirus (an arthropod-borne virus) of the genus Flavivirus that can infect birds, humans, horses, and other animals (Arroyo, Miller, Catalan, & Monath, 2001). It is primarily transmitted from infected birds to mosquitoes and then to other mammals. Birds are an excellent host for WNV because they develop a substantial enough viral load in their blood to infect mosquitoes that subsequently bite them (Marfin & Gubler, 2001). Unlike birds, humans are incidental, or dead-end, hosts because they do not continue the transmission cycle when bitten by a mosquito (Arroyo et al., 2001). There is no evidence to date that humans may become infected through contact with other infected humans, other infected mammals, or infected birds (Arroyo et al., 2001).

WNV infection features relatively minor symptoms for most people but can result in severe neurological disease and death in an extreme minority of those infected (Mostashari et al., 2001). Mild infection in humans can cause fever, malaise, enlargement of the lymph nodes, pain around the eyes, gastrointestinal symptoms, muscle pains, and headache. Less than 1 percent of all WNV human cases have a neurological component (CDC, 2001); however, the elderly and people with suppressed immune systems may develop encephalitis (inflammation of the brain) or meningitis (inflammation of the outer membrane of the brain) (Craven & Roehrig, 2001). In 1999, the first year WNV was detected in the United States, 62 infected humans were identified. Of these, 59 were hospitalized and seven died. Some estimate that the number of infections in NYC in 1999 alone actually approached 8,200 cases, including about 1,700 infections causing fever (Mostashari et al., 2001). As WNV spread (particularly to the west), the number of human cases rose dramatically, peaking in 2003 (9,862 cases). By 2004, human cases of WNV had been reported in 40 states and the District of Columbia (CDC, 2004).

Legal Responses and Environmental Health

Legal responses to the spread of WNV have varied. Many states introduced new legislation. Eight states (California, Connecticut, Idaho, Illinois, New Jersey, New York, Rhode Island, Vermont) enacted laws to combat the threat of WNV infection. Many state public health or environmental health agencies have relied on existing mosquito control and nuisance laws to control the spread of WNV. Some states have legislatively increased funding to improve surveillance of mosquito and bird populations or to conduct mosquito control measures to decrease the number of potential vectors for WNV. Others have strengthened public-nuisance laws to address environmental hazards that foster the spread of WNV. Public-education programs have been used to inform individuals about pesticides and to encourage behaviors that reduce risk of mosquito bites. These and other legal responses are further described below.

Mosquito Vector Controls

In Vermont, the General Assembly authorized the waiving of procedural requirements for obtaining a permit to apply insecticides if the threat of a WNV outbreak is imminent (H.R. 478, 2001). The state may issue permits for the use of larvacides and pupacides for mosquito control without prior public notice or comment whenever an imminent risk to public health exists because of a potential outbreak of WNV or another serious mosquito-borne illness (H.R. 478, 2001).

Recognizing that "the use of pesticides must be minimized, as unwarranted and sometimes excessive spraying can irreversibly harm the environment," the Rhode Island legislature authorized the Department of Environmental Management to purchase new and innovative mosquito control devices for use at public events (H.R. 6540, 2001). In 2004, the California legislature passed the West Nile Protection and Control Act. It requires the Department of Pesticide Regulation to consider public health risks associated with any pesticide that could potentially be used for mosquito vector control. In addition, the department must consult with the state department of health to "ensure that outbreak response is supervised appropriately and conducted by licensed personnel using sound integrated mosquito management techniques" (California Health & Safety Code, 2004).

The New Jersey State Senate considered (but ultimately did not pass) a bill in 2001 to minimize available habitats for mosquitoes by directing certain county soil conservation districts to conduct hydrology studies for stormwater structures. The legislature proposed to reduce the number of mosquito habitats through mandated hydrology studies that would determine the appropriate size of stormwater structures so as to eliminate unnecessary standing water (S. 2060, 2001).

Public-Nuisance Controls

In 2002, the Florida House of Representatives passed a bill focused on solid waste management. It specifically allocated funding to reduce the number of spare tires through recycling in response to WNV (Florida Statutes, 2002). The New York Assembly similarly considered a bill to reduce mosquito habitats by regulating scrap-tire stockpiles that often feature optimal conditions for the reproduction of mosquitoes carrying WNV (H.R. 6726, 2001). According to the legislative findings, mosquitoes reproduce at a rate up to 4,000 times greater in scrap-tire stockpiles than in their natural environment. The bill proposed to 1) eliminate current scrap-tire stockpiles, 2) force new tire retailers to accept old tires, 3) encourage recycling and reuse of old tires, and 4) create a state council to oversee scrap-tire management.

West Nile Virus Surveillance Programs

At the federal level, WNV is tracked through CDC's ArboNET program, which receives information regarding human and animal WNV cases from state and local public health departments (CDC, 2004). Some states have sought to legally bolster their own surveillance programs. The New York General Assembly, for example, is currently considering a bill to increase funding to counties for mosquito and vector surveillance, monitoring, and control programs that use effective non-spraying alternatives. County responses must be consistent with the state's WNV Response Plan; comply with pesticide permits, registrations, and labels; and be subject to environmental monitoring absent a public health threat declaration (H.R. 2823, 2005).

Public-Education Programs

Many states focus on public education as part of a comprehensive plan to decrease human exposure to infected mosquitoes (S. 4852, 2001 [New York]; S. 146, 2001 [Vermont]). Legislative requirements for public education about WNV are often vague, citing the need for "public education" (H.B. 6392, 2001 [Connecticut]) or actions to "educate the general public" (S. 4852, 2001) as part of a state's WNV plan. California lawmakers, however, adopted a resolution that directly addresses public education, declaring one week in midsummer "Mosquito and Vector Control Awareness Week." California's resolution supports public awareness as a way to 1) reduce mosquito populations on private, commercial, and public lands and 2) help people avoid potentially dangerous mosquito bites (General Assembly Con. Resolution 26, 2001). Elsewhere, public health agencies often include public education as a major component of the state's disease prevention and response plans (Connecticut Department of Environmental Protection, 2001; Florida Department of Health, 2001).

Community Responses to WNV Control Measures: A New York City Case Study

In late August of 1999, after it was determined that a cluster of encephalitis cases in Queens County, New York City, had been caused by WNV, the city immediately began applying larvicide to standing bodies of water and spraying pesticides by helicopter to control adult mosquitoes. This response was pursuant to a local law (New York City Charter [section] 315, 2004) that authorized the Mayor's Office of Emergency Management (OEM) and the city's purchasing agency to immediately declare a state of emergency, and procure pesticides and the services of licensed applicators. After cases of WNV were found in other NYC boroughs, aerial spraying of pesticides was performed across most of the city until the end of October 1999. These efforts were deemed highly successful. No human WNV infections were found in NYC in 1999 after completion of the citywide spraying, although cases continued to occur in nearby counties that chose not to spray (CDC, 2000). Advance plans for the 2000 mosquito season included 1) the extensive application of larvicides to standing bodies of water and catch basins (approximately 135,000) in the city, and 2) the subsequent potential spraying of adulticides to kill mosquitoes.

Despite the success of these interventions, legal controversy arose. New York's State Environmental Quality Review Act (SEQRA) requires that the government obtain an environmental review before applying pesticides except when "emergency actions ... are immediately necessary" to protect life and health (SEQRA, 2000). (Although the city did not conduct an environmental review prior to spraying for mosquitoes in 1999, it did not violate SEQRA because of the emergency threat of WNV). Pursuant to SEQRA, NYC's health commissioner declared that larviciding presented no significant risks to the environment and thus did not require further environmental review. The commissioner could not, however, declare that the danger to the environment (including human populations) from spraying pesticides was insignificant without further examination. As a result, a study of the effects of pesticides on humans and on natural resources was commissioned, culminating months later in the production of an environmental-impact statement (EIS). Without the EIS, the city was required in 2000 to once again invoke its emergency health powers to conduct mosquito abatement measures, including spraying. (Ultimately, the city's EIS concluded that the proposed use of pesticides to control adult mosquitoes did not present significant risks to the natural resources of the environment or the public's health.)

Of course, spraying of pesticides was not the sole intervention. Control efforts were also aimed at reducing water accumulations that served as mosquito-breeding grounds. NYC's Board of Health adopted on April 18, 2000, a resolution that 1) declared water accumulations to constitute a public health nuisance, 2) determined that such conditions existed citywide, 3) ordered all property owners or tenants to immediately eliminate all water accumulations and conditions that created them, and 4) authorized and directed the health department to abate nuisances directly if individuals failed to comply (New York Administrative Code [section] 17-148, 2000). NYC launched an extensive public education campaign urging the elimination of stagnant water and established a telephone hotline for citizens to file stagnant-water complaints. City inspectors could issue warning letters and intervene on site.

Despite these efforts during 2000, mosquito traps throughout the city detected mosquito pools that were positive for WNV. WNV-positive dead birds were also found. On July 18, 2000, the first human case of WNV in NYC was confirmed. Following CDC recommendations, NYC sprayed an ultra-low volume of pesticide (pyrethroid) within a two-mile radius of a positive bird or mosquito pool, or the residence of a human case. Application was by backpack, truck, or all-terrain vehicle, or by helicopter in inaccessible areas. The city took extraordinary steps to minimize the public's exposure to pesticides. Notices of the time and place of spraying, as well as precautions, were circulated 48 hours in advance. Most spraying was limited to the hours between 10:00 p.m. and 5:00 a.m. Police cars accompanied spray trucks. Loudspeakers warned pedestrians to go indoors. Still, some portion of the population was exposed to the fine, ultra-low-volume pesticide mist. Telephone hotline operators took reports of pesticide exposure and advised callers.

Immediately upon announcing its decision to spray adulticides in 2000, NYC was challenged by a group of organizations and individuals concerned about the environmental and human health effects of widespread pesticide use. Collectively known as the No Spray Coalition, Inc. ("coalition"), it sued New York City to halt pesticide spraying to abate the mosquito populations (No Spray Coalition v. City of New York, 2000). The coalition argued that the spraying of pesticides by the city violated

1. New York's SEQRA--this claim was later dismissed following the completion of the EIS in 2001;

2. the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which prohibits use of certain agents that have adverse environmental effects--this claim was also dismissed because FIFRA is enforced solely by the federal government and thus does not allow for private causes of actions; and

3. the federal Clean Water Act because of potential contamination of water sources. Although its claims were initially dismissed, the coalition filed suit in 2002, alleging again violations of the Clean Water Act (No Spray Coalition v. City of New York, 2002). Eventually, the federal Court of Appeals agreed that the Clean Water Act may apply to limit some environmental uses of pesticides (No Spray Coalition v. City of New York, 2003). Presently, the coalition is seeking additional review of its case in the lower court.

Conclusion

The appearance and subsequent spread of WNV throughout the country illustrates how public health activities must balance individual interests with communal health and safety. The threat of WNV infection has inspired legislative activity to improve states' abilities to educate the public, abate public nuisances, and control mosquito populations in order to limit WNV's prevalence in the United States. One of the oldest public health activities, mosquito control, requires government and the private sector to abate conditions that are conducive to the spread of diseases like WNV. WNV demonstrates the links between environmental-nuisance abatement and disease prevention, as well as the need to regulate individuals and their property to protect the general public. These activities can be the source of legal conflicts that are reflected in the sort of legislative proposals and civil litigation that occurred in New York City. Resolution of these conflicts and competing interests is not simple, but it is essential. Protecting the public's health from WNV may involve unavoidable tradeoffs, but deleteriously contaminating the environment to the detriment of others need not be one of them.

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James G. Hodge, Jr., J.D., L.L.M.

Jessica P. O'Connell

Corresponding Author: James G. Hodge, Jr., Associate Professor, Johns Hopkins Bloomberg School of Public Health, Hampton House, Room 588, 624 N. Broadway, Baltimore, MD 21205-1996. E-mail: [e-mail].