Hazardous Substances Released During Rail Transit --- 18 States, 2002--2007

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In January 2007, two separate railroad incidents involving the unintentional release of hazardous substances occurred on consecutive days in Irvine and Brooks, two Kentucky communities approximately 125 miles apart (1). Although the incidents were not causally related, they both resulted in public health consequences (e.g., increased hospital visits, evacuations, and shelter-in-place orders (Kentucky Department for Public Health, unpublished data, 2007). Subsequently, the Agency for Toxic Substances and Disease Registry (ATSDR) reviewed data from the Hazardous Substances Emergency Events Surveillance (HSEES) system to update a previous analysis involving rail events (2). The HSEES system is used to collect and analyze data regarding the public health consequences associated with hazardous-substance release events,* including those that occur during transportation. This report describes the two 2007 events in Kentucky (a non-HSEES state) and two other illustrative events in Minnesota in 2006 and in Utah in 2005, for which HSEES data were collected. In addition, this report summarizes all rail events reported to HSEES from 17 state health departments during 2002--2006.^§

Analysis of HSEES data was limited to the 78 rail events in which chemicals were released and the area of impact (i.e., the area where the plume extended) was >200 feet from the point of release. This definition was chosen because of the greater likelihood that nearby populations might be affected, compared with incidents in which chemicals did not migrate beyond the point of release. The following four event reports were selected to highlight the public health consequences that can result from hazardous-substance releases.

Event Reports

Irvine, Kentucky. On January 15, 2007, four runaway train cars rolled approximately 20 miles before colliding with two unoccupied engines outside of Irvine, Kentucky (2000 population: 2,843). One of the four cars carried butyl acetate, a flammable solvent, which ignited on impact and resulted in an explosion. Butyl acetate can cause symptoms such as skin, eye, and upper respiratory system irritation; headache; drowsiness; and narcosis (3). After the crash, residents of 20 households were evacuated because of fumes and smoke produced by the burning butyl acetate, but they were allowed to return home later that day. Approximately 3,000 Irvine residents were advised to shelter in place (i.e., stay indoors and seal access to outside air). Approximately 320 employees of nearby businesses were evacuated for 2 days until air monitoring results confirmed conditions were no longer hazardous. No injuries were reported.

Brooks, Kentucky. On January 16, 2007, a train derailed in Brooks, Kentucky (2000 population: 2,678) (Figure). The derailment involved a total of 13 tank cars, 12 of which included hazardous materials or residue from hazardous materials. Tank cars containing 1,3-butadiene, cyclohexane, methyl ethyl ketone, and maleic anhydride were allowed to burn throughout the night to destroy the hazardous materials. These chemicals were detected in air and water samples from the area surrounding the incident site; soil and shallow groundwater also were assessed (4). The two-person train crew escaped unhurt. Thirty-one persons, examined <24 hours after the incident, had symptoms that included headache, dizziness, upper and lower respiratory tract irritation, and eye irritation. Fifty-three persons in the vicinity eventually sought medical treatment at two local hospitals. A woman aged 61 years with a history of chronic obstructive pulmonary disease (COPD) was transferred to a metropolitan hospital with exacerbation of her COPD symptoms because of smoke inhalation. She was released after 2 weeks of supportive therapy.

After this incident occurred, approximately 350 persons from homes, schools, and businesses within a 1-mile radius of the release site were evacuated for 2 hours. Thirty-five residents of 15 homes were prohibited from returning home for approximately 6 weeks until contaminated plastic water lines (penetrable by released chemicals) were replaced. Approximately 300 persons from outside the evacuation area but within the path of the plume were ordered to shelter in place. In addition, an 8-mile stretch of an interstate highway approximately 0.5 mile from the release site and in the path of the plume was closed for 12 hours (5).

St. Paul, Minnesota. In May 2006, approximately 5,000 gallons of hydrochloric acid were released in St. Paul, Minnesota (2000 population: 287,151), from a stationary rail tanker at a chemical wholesaler. The rubber liner in the tanker had become displaced, allowing the acid to corrode and rupture the bottom of the tanker. A vapor cloud drifted from the site, and approximately 150 gallons of acid traveled through a storm sewer to a nearby river. Hydrochloric acid can cause skin, eye, and respiratory irritation; burns; and pulmonary edema (3). Seven persons were reported injured after contact with the vapor cloud: six members of the general public and one employee of the wholesaler. The most common injuries were respiratory and eye irritation. Six of the injured were treated at a hospital and released; the seventh person had symptoms but was not treated. Approximately 100 persons downwind from the release and in the path of the subsequent vapor cloud were evacuated for 2 hours. A shelter-in-place order was issued for other sites near the 1-square--mile evacuation area.

Salt Lake City, Utah. In March 2005, a mixture of approximately 6,500 gallons of phosphoric, sulfuric, acetic, and hydrofluoric acids corroded the inside of a stationary railcar and began leaking, causing an orange vapor cloud in Salt Lake City, Utah (2000 population: 181,743). The corrosion was attributed to improper combination of the acids because of human error. A member of the general public approximately 0.25 mile away experienced respiratory irritation and was treated on the scene. Approximately 8,000 persons downwind from the release were evacuated for 5 hours, and a shelter-in-place order was issued for a five-block area near the evacuation zone.

HSEES Surveillance of Rail Events

State health departments participating in HSEES collect data on acute hazardous-substance events from various agencies, including the National Response Center, U.S. Department of Tranportation, and state environmental and response agencies. The data are immediately entered into a secure Internet database, from which they can be accessed by ATSDR and the states. Of the 42,359 hazardous-substance releases reported to HSEES by 17 state health departments during 2002--2006, a total of 11,383 (26.9%) were transportation related, including 1,051 (9.2%) that involved rail transport. Among the rail transport events, 78 (7.4%) involved a chemical release and an area of impact that extended >200 feet from the point of release. The most common primary contributing factor in these 78 events was equipment failure (49 events [62.8%]); human error contributed to 24 (30.8%) events. A total of 103 different substances were released in the 78 rail transport events. The most common substances were diesel fuel (released along with a hazardous chemical substance) (seven events), chlorine (five), and hydrochloric acid (five); 61 (78.2%) events involved release of a single chemical.

Injuries were reported from 11 (14.1%) of the 78 rail events; a total of 144 persons were injured (Table). Among those injured, 101 (70.1%) were members of the general public, 27 (18.8%) were employees of the railroad or companies at the sites of releases, and 16 (11.1%) were responders. Of the 210 total injuries sustained by the 144 persons, the most commonly reported were respiratory irritation (104 [49.5%]) and eye irritation (33 [15.7%]). Among the 143 persons for whom medical outcome was known, 101 (70.6%) were treated at hospitals and released, and 23 (16.1%) were treated on the scene. Nine (6.3%) persons were admitted to a hospital, five (3.5%) were examined at a hospital but not treated, and two (1.4%) had symptoms but were not treated. Three persons died; a railroad employee died from trauma, and two members of the general public died from respiratory injuries.

In the 78 events, a total of 314,336 residents (range: zero to 25,480 persons; median: 2,765) lived within 1 mile of the release sites. In 63 (80.8%) of the events, residences were located within 0.25 mile of the release, affecting a total 16,074 residents (range: 0--1,820 persons; median: 123). Sensitive sites located within the 0.25-mile range included day care centers (eight), schools (eight), and nursing homes (three) (Table). Seventeen (21.8%) rail events were associated with mandatory evacuations. A total of 10,002 persons (range: seven to 8,000 persons; median: 48) were known to have been evacuated. Durations of evacuation ranged from <1 hour to 13 days (median: 5.8 hours). For 58 (74.4%) rail events, no orders were issued to evacuate or shelter in place.

Reported by: B Learn, D Thoroughman, PhD, Kentucky Dept for Public Health. R Brackbill, PhD, DK Horton, MSPH, PZ Ruckart, MPH, F Bove, ScD, M Orr, MS, V Kapil, DO, Div of Health Studies, Agency for Toxic Substances and Disease Registry.

Editorial Note:

Approximately 1.8 million carloads of hazardous substances are shipped annually by rail in the United States, including through densely populated or environmentally sensitive areas (6--8). Of these carloads, approximately 105,000 contain toxic inhalation hazard substances such as chlorine, anhydrous ammonia, and hydrochloric acid (6,7). Although rail events constitute only 2% of total hazardous-substance releases in HSEES, releases during rail transit can cause severe public health consequences, as demonstrated by the event reports and surveillance data. Notably, approximately 81% of hazardous-substance releases from rail events occurred in areas with residences within 0.25 mile, and most of the injured were members of the general public.

Although the rate of all rail incidents has declined sharply since 1980, less improvement has been observed in recent years; the rail incident rate per million train miles actually increased from 3.76 in 2002 to 4.38 in 2004, before decreasing to 4.08 in 2005 (6). In recent years, concern over railroad safety has been elevated by major incidents such as the Graniteville, South Carolina, train collision in January 2005 that released 11,500 gallons of chlorine gas, caused nine deaths, and resulted in 529 persons seeking medical treatment (2,6). In response, the U.S. Department of Transportation (DOT) and the Federal Railroad Administration launched the National Rail Safety Action Plan in 2005 (9). This plan targets the most frequent, highest-risk causes of train incidents (e.g., equipment failure or human error) and is aimed at improving emergency preparedness and the safe handling of hazardous materials. In addition, in 2006, DOT proposed new rules requiring rail carriers to compile annual data on hazardous materials shipments and use these data to evaluate safety and security risks and alternative routing options (7).

The findings in this report are subject to at least four limitations. First, HSEES data were collected from only 17 states; therefore, the data represent only a proportion of hazardous-substance events that occur in the United States. Second, HSEES data do not fully integrate data on hazardous-substance releases that are collected by federal and state agencies. Moreover, acute release data are not effectively linked to other public health and environmental data (e.g., population, demographics, and locations of schools, nursing homes, and day care centers). Improved surveillance might place hazardous-substance incidents in community and industry contexts and enable more thorough analyses of the causes and effects of incidents. Third, reporting of events to HSEES is not mandatory, and participating state health departments are not informed about every event. Finally, by law, petroleum-only releases are excluded from HSEES data collection.

Additional preparedness measures (e.g., planning and training of local response agencies and the public and establishment of notification mechanisms, escape routes, shelter-in-place protocols, and emergency shelters) are needed to respond to hazardous-substance rail incidents. In addition, new concerns have been raised since September 11, 2001, regarding the potential for terrorist attacks on railcars carrying large quantities of hazardous substances. Increased collaboration among railroad stakeholder organizations (e.g., environmental, transportation, industry, public health, public safety, and research) could result in better mechanisms to monitor rail substance-release events and use available data to identify vulnerabilities and promote safer technologies and practices.

The findings in this report are based, in part, on contributions by participating HSEES states; Kentucky Dept for Public Health; D Reeves, US Dept of Transportation; and B Lewis, Agency for Toxic Substances and Disease Registry.

References

* An HSEES event is defined as one that involves the release or threatened release of a hazardous substance or hazardous substances that meet minimum criteria. A hazardous substance is one that can be expected to cause an adverse health effect.

The analysis included events recorded in HSEES for 2002--2006. Twelve states participated in HSEES during the entire period: Colorado, Iowa, Louisiana, Minnesota, New Jersey, New York, North Carolina, Oregon, Texas, Utah, Washington, and Wisconsin. Five additional states participated during portions of the period: Alabama (2002--2003), Florida (2005--2006), Michigan (2005--2006), Mississippi (2002--2003), and Missouri (2002--2005).

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