Unplanned Releases and Injuries Associated with Aerial Application of Chemicals, 1995-2002

Article excerpt


Aerial application is an efficient means of targeting chemical application to increase crop production. Aerial-application pilots, however, have a high rate of fatalities compared with pilots in other industries (Centers for Disease Control and Prevention [CDC], 2004; Suarez, 2000). Along with the risk of aircraft crash, there is an added risk of exposure to hazardous substances. Unplanned or uncontrolled releases of pesticides or other hazardous substances may occur during any phase of the aerial-application process, including mixing and loading of chemicals into the aircraft, application of the chemicals, and servicing of the aircraft (Minnesota Department of Agriculture [MDA], 2000; University of Nebraska, 1996). Accidental releases can affect not only agricultural chemical-application workers, but also others entering the area. For this report, data from the Agency for Toxic Substances and Disease Registry's (ATSDR's) Hazardous Substances Emergency Events Surveillance (HSEES) system were analyzed to 1) describe the number and type of unintended acute releases of hazardous substances associated with aerial application during 1995-2002, 2) describe associated human health consequences, and 3) review measures to reduce releases and associated injuries. Data from the National Transportation Safety Board (NTSB) were also reviewed and compared with HSEES data.


Seventeen state health departments participated in the HSEES system during 1995-2002. Alabama, Colorado, Iowa, Minnesota, Mississippi, Missouri, New York, North Carolina, Oregon, Texas, Washington, and Wisconsin participated for the entire period. Five states participated for part of this period: Louisiana (2001-2002), New Hampshire (1995-1996), New Jersey (2000-2002), Rhode Island (1995-2001), and Utah (2000-2002). Participating states collected data from a variety sources, such as state and local emergency responders, environmental and health agencies, poison control centers, hospitals, and the news media.

An HSEES event is an uncontrolled, illegal, or threatened release of a hazardous substance that requires removal, cleanup, or neutralization according to federal, state, or local law. A hazardous substance is one that can be reasonably expected to cause an adverse health effect. Events involving only a threatened release were included if the threat of release resulted in an action to protect public health, such as evacuation. Events involving petroleum only were excluded. Victims were defined as any person sustaining at least one symptom, such as eye irritation, in conjunction with the hazardous substance release.



Data specifically attributed to aerial-application accidents in the National Transportation Safety Board's (NTSB's) Aviation Accident Database were also reviewed for 1995-2002 for states participating in HSEES. By NTSB definition, these accidents involved substantial damage to the aircraft or injury to those in the aircraft, but did not necessarily involve release of hazardous substances. Reporting of crashes or injuries to NTSB is mandatory.

Results and Discussion

During 1995-2002, 54,090 events were recorded in the HSEES system. Ninety-one events, including one threatened release, involved aerial application. The number of aerial-application events was relatively constant from 1995 to 2000, but the number decreased in 2001 and 2002 (Figure 1). Three hundred and fifty NTSB aerial-application accidents were identified for the corresponding HSEES states. The number of these accidents per year also appears to be decreasing, with 39 to 54 per year for 1995-2000 and 34 to 35 per year in 2001-2002.

Seasonal trends were similar for the HSEES data and the NTSB data (Figure 2, Figure 3). Most HSEES and NTSB events occurred during May to September. Most of the 81 HSEES events for which the time was known occurred in the morning (nine events per hour between 7:00 a. …