Large mass casualty gas explosions and catastrophic oil spills are widely reported
and receive considerable regulatory attention. Smaller, less catastrophic petroleum
product releases are less likely to receive publicity, although study of these incidents
might help focus and prioritize prevention efforts. To describe the causes and health
impacts of petroleum product release incidents (including gas explosions and oil spills),
the Agency for Toxic Substances and Disease Registry (ATSDR) analyzed 2010–2012 data
from the National Toxic Substance Incidents Program (NTSIP). A total of 1,369 petroleum
product release incidents were reported from seven states, resulting in 512 injuries
and 36 deaths. Approximately one fourth of the incidents were associated with utilities,
and approximately one fifth were associated with private vehicles or residences. Approximately
10% of petroleum product releases resulted from inadvertent damage to utility lines.
Understanding the characteristics of acute petroleum product releases can aid the
public and utility workers in the development of preventive strategies and reduce
the morbidity and mortality associated with such releases.
Petroleum is refined to produce gasoline, heating oil, propane, and other fuels (1).
If not managed properly, these products can adversely affect humans, wildlife, and
the environment (2). Adverse health effects can include skin irritation, eye irritation,
dizziness, headache, nausea and, and in extreme cases, death (2). Because petroleum
is widely used, unintentional acute releases can occur almost anywhere.
In 2010, ATSDR established NTSIP to collect information useful for reducing morbidity
and mortality associated with acute toxic substance releases.* State NTSIP partners
collect information pertaining to acute petroleum and nonpetroleum releases and the
public health effects of those releases and enter it into a web-based application.
Acute nonpetroleum releases include but are not limited to any substance that, after
release into the environment and upon exposure, ingestion, or inhalation, could cause
morbidity or mortality. Nonpetroleum releases include chemical, biologic, radiologic
and medical materials (3). However, NTSIP limits collection of information regarding
releases of petroleum to those that result in an injury or a public health action
(e.g., evacuation, shelter-in-place, alternative water usage, ban on fishing, health
advisory, health investigation, prohibition against livestock or produce consumption,
water intake shutdown or environmental sampling, and well survey). Additionally, NTSIP
excludes petroleum-related incidents for which the only source of petroleum was the
fuel tank of a vehicle involved in a crash.
During 2010–2012, seven states contributed data to NTSIP: Louisiana, New York, North
Carolina, Oregon, Tennessee, Utah, and Wisconsin. To identify petroleum releases,
ATSDR first searched the NTSIP system for “petroleum incidents” by searching on the
chemical name variable for petroleum products listed in the 2010 NTSIP training manual
(3). ATSDR then reviewed the comments and synopsis fields of the identified records
to confirm that they described petroleum incidents. Descriptive statistical analyses
comparing petroleum and nonpetroleum incidents were then performed.
NTSIP recorded 8,684 single-substance incidents during 2010–2012, of which 1,369 (15.8%)
were petroleum-related. Of the 1,369 NTSIP petroleum-related incidents, 259 (18.9%)
incidents included injuries (Table 1). In addition, 512 (15.1%) of the 3,399 persons
injured in all NTSIP incidents were injured in petroleum incidents. The most commonly
reported contributing factors for petroleum incidents were equipment failure (51.7%)
and human error (40.2%). The remaining contributing factors were weather (4.3%), intentional
or illegal acts (2.2%), and other factors (1.6%). Among the 1,369 petroleum incidents,
1,170 (85.5%) occurred in fixed facilities.
The utilities industry accounted for the greatest number of petroleum-release incidents
(327 [23.9%]) (Table 2); most of these incidents (253 [77.4%]) were related to natural
gas distribution. Of the utility releases, 131 (40.1%) involved lines damaged or cut
because of errors by contractors, construction workers, or residents. A total of 14
(4.3%) of the 327 utility releases resulted in injuries, with a total of 27 persons
injured (Table 2).
The second most commonly reported type of petroleum releases (296 [21.6%]) occurred
in private vehicles and residences. These incidents were the most likely (105 [40.5%])
to result in injury and caused injuries to 236 persons (46.1%) (Table 2). Of the 105
petroleum-release incidents with injured persons, 59 (56.2%) incidents involved explosion
or fire or both.
For both petroleum and nonpetroleum incidents, most injuries were to members of the
general public, followed by employees (Table 3). Petroleum incidents resulted in a
higher percentage of persons admitted to the hospital and deaths compared with nonpetroleum
incidents (Table 3). The most commonly reported injuries for petroleum incidents were
burns (32.5%) and trauma (24.6%). Petroleum incidents were less likely than nonpetroleum
incidents to result in persons requiring decontamination (10.4% compared with 21.9%)
Illustrative Case Reports
While a subcontractor was installing cable lines, he hit a 2-inch (51 mm) natural
gas line. Natural gas leaked into the sewer system and into a townhouse, which exploded.
One member of the public, two utility workers, and two firefighters were injured in
the explosion. They had burns, trauma, and shortness of breath. All injured persons
were treated at the hospital, but none were admitted. The gas was turned off, and
hundreds of neighbors were evacuated for 24 hours.
A neighbor smelled natural gas and called utilities. Utility personnel investigated,
but did not find a gas leak. Later, a nearby house exploded, injuring three members
of the public. Two persons were admitted and treated at a hospital for burns. The
third person died in the explosion. The area was evacuated for 6 days, affecting approximately
20 persons. The American Red Cross responded to provide assistance.
Petroleum release incidents have the potential to cause mass casualties and environmental
contamination. In 2010, two incidents of acute, unintentional releases of petroleum
products received prominent attention in the news media (4–7). One was a Pacific Gas
and Electric gas line explosion in San Bruno, California. A 30-inch natural gas pipeline
ruptured after reports from residents in the neighborhood stating they smelled gas.
This release led to an explosion that left 35 homes burned, eight persons dead, and
30 more injured (6). The second incident was in Enbridge, Michigan, were a ruptured
pipeline released more than 800,000 gallons of crude oil into the Kalamazoo River
(5), resulting in serious environmental impacts and various adverse health effects
(e.g., headache, nausea, and respiratory symptoms) in nearby residents (7).
NTSIP data from seven states for 2010–2012 indicate that petroleum incidents accounted
for 15.8% of all toxic substance releases, and most of the petroleum incidents involved
utilities. Nearly half of the utility incidents involved homeowners or construction
contractors damaging or cutting lines. Petroleum releases caused by cut lines can
be prevented if the public and construction professionals follow one simple precaution:
call 811. Many underground utility pipes and conduits, but not all, are marked by
signs above ground signaling their location. Each state has different rules and regulations
governing digging, and some rules are more stringent than others. The telephone number
811 has been nationally designated to eliminate confusion over multiple “Call Before
You Dig” numbers across the country. Dialing 811 connects callers with local centers
that notify the appropriate local utilities, who then send crews to the requested
site to mark the approximate location of underground lines at no charge (8).
Private vehicles and residences had the second greatest number of total petroleum
release incidents, the greatest number of incidents involving injured persons, and
the greatest total of injured persons. Many of these incidents were attributable to
propane tank explosions, natural gas leaks, and gasoline misuse (e.g., using gasoline
with charcoal grills and fireplaces).
The findings in this report are subject to at least three limitations. First, NTSIP
data only include petroleum incidents that result in an injury or public health action;
therefore, petroleum incident data are skewed toward higher percentages with injuries
and evacuations. Second, because home incidents with no injury or public health action
are not included in NTSIP, these data do not include all home incidents. Finally,
with only seven states participating in NTSIP, no generalizations can be made regarding
other states or data nationally.
What is already known on this topic?
Most petroleum products are highly flammable, and many can explode. Unintentional
releases of petroleum products can cause significant morbidity, mortality, environmental
damage, and financial loss.
What is added by this report?
During 2010–2012, a total of 1,369 unintentional petroleum product release incidents
were reported by seven states to the National Toxic Substance Incidents Program. The
incidents resulted in injuries to 512 persons and 36 deaths. Forty-six percent of
the incidents were related to utilities, private residences, or private vehicles.
The greatest number of petroleum release incidents resulted from cut utility lines
or gas leaks, and burns were the most common type of injury.
What are the implications for public health practice?
The most common causes of petroleum release incidents are preventable. Contractors,
construction workers, homeowners, and renters need to understand the potential health
and environmental consequences of damaging gas lines when digging. Additionally, members
of the public need to be made more aware of how to recognize gas leaks and of what
can happen if they misuse petroleum products.
Because of the danger posed by petroleum incidents and their continuing occurrence,
strategies to prevent releases are needed. Based on the NTSIP data, a comprehensive
approach to construction worker training regarding ruptured line prevention might
reduce petroleum release incidents and their health consequences. In addition, education
is needed to inform the public regarding the safe use of petroleum products and the
need to be able to recognize a gas leak and know what steps to take to prevent explosions