Basic Calculations for Occupational Safety and Environmental Health Professionals - Mathematics and Statistics for the Environment - page 384

causing loss or injury which is not due to any fault or misconduct on the part of the person
injured, yet entitles some kind of legal relief.” Are you confused? Stand by. The following
definition will help clear your heads (Haddon et al., 1964, p. 28):
With rare exception, an accident is defined, explicitly or implicitly, by the unexpected occurrence of physical
or chemical change to an animate or inanimate structure. It is important to note that the term covers only
damage of certain types. Thus, if a person is injured by inadvertently ingesting poison, an accident is said to
have taken place; but if the same individual is injured by inadvertently ingesting poliovirus, the result is but
rarely considered accidental. This illustrates a curious inconsistency in the approach to accidents as opposed
to other sources of morbidity, one which continues to delay progress in the field. In addition, although
accidents are defined by the unexpected occurrence of damage, it is the unexpectedness, rather than the
production and prevention of that damage per se, that has been emphasized by much of accident research.
The approach is not justified by present knowledge and is in sharp contrast to the approach to the causation
and prevention of other forms of damage, such as those produced by infectious organisms, where little, if
any, attention is paid to the unexpectedness of the insults involved, and only their physical and biological
nature is emphasized—with notable success.
Now you should have a better feel for what an accident really is; however, another defini-
tion, perhaps one more applicable to our needs, is provided by safety experts, the authors
of the ASSE Dictionary of Safety Terms . Let's see how they define accident:
An accident is an unplanned and sometimes injurious or damaging event which interrupts the normal prog-
ress of an activity and is invariably preceded by an unsafe act or unsafe condition thereof. An accident may
be seen as resulting from a failure to identify a hazard or from some inadequacy in an existing system of
hazard controls. Based on applications in casualty insurance, an event that is definite in point of time and
place but unexpected as to either its occurrence or its results.
In this text we use the ASSE definition of accident.
Accident analysis —A comprehensive, detailed review of the data and information compiled
from an accident investigation. An accident analysis should be used to determine causal
factors only, and not to point the finger of blame at any one. Once the causal factors have
been determined, corrective measures should be prescribed to prevent recurrence.
Accident prevention —The act of averting a circumstance that could cause loss or injury to a
person.
Accommodation —The ability of the eye to quickly and easily readjust to other focal points
after viewing a video display terminal (VDT) so as to be able to focus on other objects,
particularly objects at a distance.
Acoustics —In general, the experimental and theoretical science of sound and its transmis-
sion; in particular, that branch of the science that has to do with the phenomena of sound
in a particular space such as a room or theater. Safety engineering is concerned with the
technical control of sound and involves architecture and construction, studying control of
vibration, soundproofing, and the elimination of noise to engineer out the noise hazard.
Action level —Term used by OSHA and the National Institute for Occupational Safety and
Health (NIOSH), a federal agency that conducts research on safety and health con-
cerns, and defined in the Code of Federal Regulations (CFR), Title 40, Protection of
Environment. Under OSHA, an action level is the level of toxicant that requires medi-
cal surveillance, usually 50% of the permissible exposure level (PEL). Note that OSHA
also uses action levels in ways other than setting the level of a toxicant. For example, in
its hearing conservation standard, 29 CFR 1910.95, OSHA defines the action level as
an 8-hour time-weighted average (TWA) of 85 decibels measured on the A-scale, slow
response, or equivalently, a dose of 50%. Under 40 CFR 763.121, action level means an
airborne concentration of asbestos of 0.1 fiber per cubic centimeter (f/cc) of air calculated
as an 8-hour time-weighted average.
Acute —Health effects that show up a short length of time after exposure. An acute expo-
sure runs a comparatively short course and its effects are easier to reverse than those of a
chronic exposure.