Naval operational medicine institute
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- Pre-mishap Planning Checklist OPNAVINST 3750.6Q The Naval Aviation Safety Program reviewed
- Local civilian Medical Examiner/Coroner contacted
- Liaison with key personnel
- Brief instructions provided to supporting facilities: ER Drawing of samples Handling of flight gear Lab
- SAR equipment inventoried inspected
- Identification of fatalities; support personnel identified
- List of Key phone numbers and points of contact
- MEDICAL AND LABORATORY PROCEDURES REQUIRED POST-MISHAP 1. Physical Examinations.
- 2. Radiographs (X-Rays).
- Laser Exposure
- Definition
- _________________________________ |______________
- The Practicalities of LASER Protection
- NOTIFY YOUR INTELLIGENCE OFFICER OF YOUR FINDINGS.
- Category
- Major Routes of Exposure
Crash forces There are several technics for the determination of crash forces. Some involve mathmatical modeling, other are based on autopsy findings. AFIP and the Safety Center can assist in determining whether the crash forces were in the potentially survivable range. Many Aerospace Medicine Specialists, and AMSO's attend a 2 week course in this subject as part of their training. If this is a pertinent part of any mishap investigation, especially those near the edge of the survivability envelope, don't hesitate to ask for assistance.
Depending on the condition of the remains, autopsy may be able to determine the cause of death, and relate the findings to the evidence in the wreckage. If there is any question whether an autopsy might be illuminating, telephone (or message) consultation with AFIP should be accomplished. Although the pathologist can rarely work miracles with 8 ounces of incinerated tissue, in appropriate circumstances, an autopsy can be most helpful in reconstructing what happened. The investigating FS should attend the postmortem if possible. If the autopsy is not performed by AFIP, the FS should ensure that the following specimens are obtained at autopsy whenever possible:
The pathologist may brief Board members, if they are available, and will submit a report, but participation by the FS will allow him to answer other question raised by Board members later. AFIP conducts an Aerospace Pathology course annually. In addition to the exceptional in-house laboratory services, AFIP can tap the resources of several other agencies. When appropriate, the FBI or the Bureau of Alcohol, Tobacco, and Firearms can assist with identification, or when hijacking, sabotage, or other explosion is a possibility. NTSB has computer capability to reconstruct a 3-D projection of the flight path from radar tapes. The more tracking stations providing data, the better the output. They can also provide assistance in evaluating crash forces as described above. Some of the Service research labs can provide assistance in answering specific questions. Simulators may offer insights into what the pilot was experiencing prior to the crash and direct the investigation along fruitful lines (e.g. disorientation, GLOC). Re-flying the mission profile (with appropriate safety checks) may be similarly helpful. In summary, when considering the mishap scenario, think of evidence which would support or reject a hypothesis; try to imagine or ask experienced investgators how such evidence might be obtained; and consult with the Board to determine whether that line of investigation is likely to be fruitful. If the answer is "yes", ask for assistance. Pre-mishap Planning Checklist
MEDICAL AND LABORATORY PROCEDURES REQUIRED POST-MISHAP 1. Physical Examinations. While the responsibility for performing the required physical examination lies with the first "Flight Surgeon" to examine the survivors and victims, an initial examination should be conducted by the first member of the medical department to contact the survivors/victims according to the following order of preference:
2. Radiographs (X-Rays). Radiographs (x-rays) shall be performed as clinically indicated. After all ejections, bailouts, and crashes with or without suspected back injuries, full spinal x-rays are required.
While biological/laboratory samples are required only for Class A and B mishaps, and those Class C mishaps which are investigated by a Flight Surgeon, the exact class of the mishap is frequently not known until it is too late to obtain meaningful laboratory samples. For this reason, the following rule of thumb should be used: obtain laboratory samples any time there is damage of any extent to an aircraft or other government property, or any time someone is injured in association with flight operations. Samples which are later determined to be superfluous may be discarded.
Sufficient blood and urine shall be drawn from each member of the flight crew and from support personnel such as handlers, controllers, or LSO's, who may have been involved in the mishap, for the determination of:
The above samples should be labeled with NAME, SSN, DATE, AND TIME COLLECTED and turned over to the flight surgeon for submission to appropriate laboratories. A legal chain of custody is not required, but samples should be secure from damage or tampering.
Laser Exposure
Definition: LASER - Light Amplification by Stimulated Emission of Radiation
Lasers are of military usefulness by all nations for range finding, target designation and tracking. They may also be used as weapons for harassment and physical injury of opposing forces. They may be disruptive of operations by:
Laser Physics: If energy is applied to a substance causing electrons to jump from the basal to the excited state, the same amount of energy is released as electrons return to the basal state. If that energy is released as light, the light will be of the wavelength (color) characteristic for that substance and the energy required to excite it. Thus, only a single wavelength is produced when an electron in a given molecule returns to its basal state. If that light is collimated by mirrors into a unidirectional beam, it will tend to retain its energy until dissipated by distance through the atmosphere, each wavelength absorbed by the atmosphere at different rates. So, some wavelengths will retain their energy and focus over greater distances than others. How intense the laser beam is depends upon the energy applied to excite the electrons (and therefore that released) and the excitability of the substance used. Therefore, a ruby laser is not necessarily stronger or more energetic than a neodymium laser, but the wavelengths produced have quite different properties. Each LASER will function at a discrete frequency (depending on the substance used), some of which are in the visible range, some not. Some LASER substances have more than one energy level capability on excitation, and therefore may radiate at more than one discrete frequency if different energy levels are applied.
Atmospheric conditions will have an effect on LASER beams by diffusion or absorption by water vapor, smoke, etc., again depending on wavelength. Generally all LASER beams widen at least a small amount with distance. Unfortunately, the human eye has the capability of concentrating the LASER beam by a factor of about 100,000 times and focusing it on the retina. The temperature at the point of focus at the retina may be in the neighborhood of 1000 degrees, causing coagulation and destruction of that small area or, if a blood vessel is involved, a rupture of that vessel and hemorrhage into the vitreous with subsequent loss of vision. Or, since there are no pain fibers in the retina, damage may go undetected until it is discovered that there is a loss of some portion of the visual field. It is also worth noting that LASER beams may be reflected off mirror-like surfaces and picked up by the eye, losing some energy in transmission, but still dangerous. Skin burns are quite unlikely given the powers used and distances on the battlefield, and since skin does not concentrate the beam as the eye does. The cornea will not allow all wavelengths to pass through, but acts somewhat like a filter. Wavelengths above 1300 nm (far infrared) are absorbed by the cornea and lens and may produce damage to these structures while the retina is undamaged. Thus, visible and near infrared LASERs may cause damage to the retina while far infrared LASERs cause damage to the cornea and lens structures ultimately leading to corneal scarring and cataract formation.
......Retinal Damage.................|...Corneal Damage...... | UV Visible Light Infrared | Far Infrared | 100nm.....400nm...........700nm......|..........110,000nm |
| | | | | | Ar H-N R G N CO2 (Argon He-Neon Ruby Gallium Neodymium CO2)
LASER Eye Protection Just as with any other optical media, filters may be employed to absorb LASER light before it reaches the eye to cause damage. Unfortunately, if one were to filter out all the LASER wavelengths available, the result would be a filter which no one would be able to see through. The compromise is to filter out those frequencies most likely to be used in LASER operations, leaving as much usable visible spectrum as possible. Two examples of LASER protective goggles are shown with their absorption spectra.
| 100nm.......400nm............700nm......…....|.....110,000nm _________________________________|______________ | | | | | | | Ar H-N R G N | CO2 | EEK-3/P.......................xxxxx.........|.................. | LG-Bxxxxx.....................xxxxxxxxxx....|......xxxxxxxx.... ........Retinal Damage...............................Corneal...
Note that while the EEK-3/P would only block the Neodymium wavelength, but the aircraft canopy would block the far infrared and provide some additional protection. The LG-B goggle provides protection against several wavelengths, but would also block out considerable amounts of visible violet and blue-green wavelengths, degrading normal vision and particularly night vision. Unfortunately, there are literally hundreds of different LASERs with different wavelengths available. The Practicalities of LASER Protection When operating in the neighborhood (5 mi) of U.S. deployed neodymium LASERs, eye protection at the 1040 nm wavelength is needed to prevent eye damage from this invisible wavelength device. This does not help much when confronted by opposing forces who may use different wavelength devices or multiple devices. The fact is that there is no good way to predict what might be used. We do know that there have been a number of incidents reported in which the Soviets have practiced their target designation on our aircraft and ships. At this time the recommendations are to use protection against neodymium when that is the one most likely to be used, and LG-Bs when unknown frequency LASERs are the potential threat. At night, there is greater threat of eye damage due to enlarged pupillary opening, and so LASER protection is recommended when operating within 10 miles of suspected systems. It is also recommended that people not fixate on a target with LASER use potential, but rather to one side of it. The rational for that is to minimize the possibility of central retinal burn and complete visual loss. Obviously, when LASERs are being used around friendly forces, they cannot be trained on ships, aircraft or uncleared ground. It is very important that LASER exposure incidents be evaluated and reported in order to gather as much data as possible in an attempt to determine wavelengths being used, allowing use of appropriate protection.
The flight surgeon should be alert to the possibility of laser incidents which may be encountered. A high index of suspicion is necessary because laser damage may be produced without any particular immediate awareness of the event by the patient. Any such events need to be evaluated and reported.
PLEASE QUALIFY AND QUANTIFY THE ABOVE TO THE BEST OF YOUR ABILITY. DESCRIBE ANY OTHER OBSERVATIONS YOU FEEL MAY BE PERTINENT TO THE LIGHT INCIDENT BASED ON YOUR EXAMINATION, TESTING, TREATMENT, AND INTERACTION WITH THE PATIENT.
NOTIFY YOUR INTELLIGENCE OFFICER OF YOUR FINDINGS. FORWARD MEDICAL INFORMATION TO DIRAFMIC FT. DETRICK MD//AFMIC-SA
Points of Contact: Industrial Hygiene (IH) consultation can be obtained from:
If these sources are unavailable, or unable to meet your needs, contact the nearest Navy Environmental Preventive Medicine Unit (EPMU).
* Call your local DSN operator to see if applicable geographical area voice codes are required. Message address: NAVENPRVNTMEDU - TWO, NORFOLK, VA (etc)
Toxicity usually depends upon the dose and the duration of exposure. Simultaneous and consecutive exposure to more than one chemical may result in additive, synergistic, or potentiated effects. Likewise, chemical antagonism, functional antagonism, competitive antagonism, and noncompetitive antagonism may be factors to consider. Toxicologic evaluation involves several concepts which must be defined. Risk denotes the probability (expected frequency) that a chemical will produce undesirable effects under specified conditions. NEL (no effect level) is the maximum dose that has not induced any sign of toxicity in the most susceptible species of animals tested and using the most sensitive indicator of toxicity (not applied to carcinogens). There is no threshold defined for carcinogens because cancer cells can be induced by a single change in the cellular genetic material and they are self-replicating. The dose-response relationship is graphically displayed by plotting the frequency of an event vs. the dose on a log scale, which results in a sigmoid-shaped curve. The portion of this curve between 16-84% response is nearly linear and represents one standard deviation each direction from the mean.
The LD50 is also utilized to classify the toxicity of substances, as demonstrated in the following: Category LD50 Supertoxic ..........................................…..5mg/kg Extremely toxic.........................................5-50 mg/kg Highly toxic........................................…...50-500 mg/kg Moderately toxic.......................................0.5-5 g/kg Slightly toxic........................................…….5-15 g/kg Practically non-toxic...............................……..15 g/kg
Duration and frequency of exposure are also important parameters:
Toxic substances may be excreted as the parent chemicals, as metabolites, or as conjugates. Generally, when xenobiotic metabolism (biologically active but nutritionally valueless) results in more polar chemicals, they are more readily excreted by the kidneys. However, in some cases, the metabolite is more toxic (termed bioactivation). Conjugation reactions are of several types, including glucuronide formation, sulfate conjugation, methylation, acetylation, amino acid conjugation, and glutathione conjugation. Glucuronide formation is the most common and important. Adipose tissue presents a storage depot for lipid-soluble substances.
Inhalation -- the most important in industry. Ingestion -- most important in civilian exposure, least important in industry. Percutaneous -- rare and seldom serious.
1. Substitution. This implies using a less hazardous material, however, the substituted material seldom works either as well or as cheaply. Substitution is the best type of control. 2. Engineering controls. This involves placing a permanent barrier between man and the hazard. It can be simple or it can be very expensive. Engineering controls are the next best type of control. 3. Personal protective devices. These are self-donned temporary barriers. They often work well, however, a sizeable number of workers simply cannot be relied upon to use the devices. 4. Administrative controls. This entails setting limits, or educating those who may be exposed. Although important, it is the most difficult of the controls to enforce and should not be relied upon routinely. GLOSSARY PEL - Permissive Exposure Limit -- The maximum permissible concentration of a toxic substance (averaged over eight hours) to which an employee may be exposed, by directive. A legal limit that takes into account both chronic and acute effects. TLV - Threshold Limit Value -- A time weighted average exposure over an eight hour day, five day week, from which no acute ill effects occur. Excursions above the TLV are permitted if properly compensated with appropriate times below the TLV. This is a practical limit developed by industry prior to OSHA which takes into account only acute effects and contains a generous safety factor. TLV-C - Threshold Limit Value - Ceiling -- a value not to be exceeded even briefly. STEL - Short Term Exposure Limit -- A legal fifteen minute time limited exposure which may not be exceeded. OSHA - Occupational Safety and Health Administration -- A Federal Bureau and a political organization empowered to enforce Federal Safety Standards. It was organized in 1970. NIOSH - National Institute of Occupational Safety and Health -- Responsible for research, development and publishing of standards. This is a scientific organization. ACGIH - American Conference of Governmental Industrial Hygienists. Carcinogenesis - The ability to induce malignant neoplasm. Harms a single individual. Effects this generation. Mutagenesis - The ability to change genetic material. Harms the succeeding generations. Teratogenesis - The ability to cause birth defects by direct effects on the fetus. Harms the next generation. Vapor - The gaseous phase of a material which is mostly solid or liquid at room temperature (e.g. gasoline). Aerosol - A dispersion of particles, either solid or liquid, of microscopic, size in a gaseous medium. Mist - An aerosol of suspended liquid droplets (e.g. fog). Fume - An aerosol of solid particles (0.1 microns or less) generated from condensation from a gaseous state, usually after volatilization from metals (as a cutting torch on lead). Smoke - An aerosol of carbon particles (0.1 microns or less) of very small size mixed with droplets of various things. Dust - An aerosol of solid particles of 0.1 to 5.0 microns (eg. talc).
Toxic - An inherent capacity to produce illness or injury when in physical contact with a living cell. Toxicity does not necessarily imply hazard. Hazardous -- For purposes of discussion, a substance which is toxic, exposure is reasonably likely, and harmful effects are likely. Threshold Value -- The level below which there is no effect. This involves determining exactly when "approaching zero" is replaced by "zero." Very difficult to define, much less determine. Voids -- Voids are "unused" spaces aboard a ship that are closed and not ventilated for months at a time. Rust formation consumes available oxygen. They may be entered safely with a source of supplied air or generated oxygen. An organic vapor mask or a bandanna over the nose and mouth is not adequate.
Toxic Substances A major difficulty in the study of toxicology is that there are too many toxicants. The following are substances that you may encounter while you are practicing aviation medicine:
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