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PubMed2006

Biotic and abiotic regulation of lightning fire initiation in the mixedwood boreal forest.

Lightning fire is the dominant natural disturbance of the western mixedwood boreal forest of North America. We quantified the independent effects of weather and forest composition on lightning fire initiation (a detected and recorded fire start) patterns in Alberta, Canada, to demonstrate how these biotic and abiotic components contribute to ecosystem dynamics in the mixedwood boreal forest. We used logistic regression to describe variation in annual initiation occurrence among 10,000-ha landscape units (voxels) covering a 9 million-ha study region over 11 years. At a voxel scale, forest composition explained more variation in annual initiation than did weather indices. Initiations occurred more frequently in landscapes with more conifer fuels (Picea spp.), and less in aspen-dominated (Populus spp.) ones. Initiations were less frequent in landscapes that had recently burned. Variation in initiation was also influenced by joint weather-lightning indices, but to a lesser degree. For each voxel, these indices quantified the number of days in the fire season when moisture levels were low and lightning was detected. Regional indices of fire weather severity explained substantial interannual variation of initiation, and the effect of forest composition was stronger in years with more severe fire weather. Our study is a conclusive demonstration of biotic and abiotic regulation of lightning fire initiation in the mixedwood boreal forest. The independent effects of forest composition emphasize that vegetation feedbacks strongly regulate disturbance dynamics in the region.

Alberta↗
PubMed2000

[Severe lightning pain during spinal anesthesia in a patient with diabetic neuropathy].

A 71-year-old woman with diabetic neuropathy who had undergone amputation of the right lower leg for diabetic gangrene 4 years previously, experienced severe lightning pain in both legs during spinal anesthesia. She was scheduled for skin grafting for a burn ulcer on her left foot. Her preoperative physical examination revealed hypesthesia in both legs due to diabetic neuropathy. Spinal anesthesia was performed with a combined spinal-epidural needle at the L 4-5 interspace using 2.0 ml of 0.3% hyperbaric dibucaine in the left lateral position. The region of hypesthesia was spread below Th 4. Ten minutes later, she complained of severe lightning pain in both legs and midazolam 1 mg was administered intravenously against agitation. The severe lightning pain diminished after the administration of pentazocine 7.5 mg intravenously in the recovery room. There was no worsening of neurological findings 5 hours later when the effect of spinal anesthesia disappeared. This clinical picture seems to be different from that of reported cases of phantom limb pain during spinal anesthesia in which severe lightning pain occurred in both legs. This case suggests that patients with diabetic neuropathy might develop severe lightning pain during spinal anesthesia using dibucaine.

Aged↗
PubMed1997

A survey of lightning policy in selected division I colleges.

OBJECTIVE: The purpose of this research was to investigate the hazards of lightning for participants in outdoor athletics and to determine the existence of, and assess the nature of, lightning safety policy at the collegiate level. DESIGN AND SETTING: We used data from the National Severe Storms Laboratory in Norman, Oklahoma, and from a survey of Division I institutions. SUBJECTS: The 48 National Collegiate Athletic Association Division I (football) universities in Florida, Michigan, Pennsylvania, North Carolina, and New York. MEASUREMENTS: Athletic trainers at all of the selected 48 Division I institutions responded to the telephone survey. RESULTS: Florida, Michigan, Pennsylvania, North Carolina, and New York led the country in lightning deaths and injuries from 1959-1994. Only 8% (n = 4) of the institutions surveyed in these states have a written policy regarding lightning safety. CONCLUSIONS: This study demonstrated the lack of lightning safety policy in the surveyed universities and the need for a systematic plan of action to make fields safer for all who are involved in outdoor sport activities.

Journal Article↗
PubMed2006

[The spectral properties of an intense lightning return stroke].

The spectrum in the range of 400-600 nm from the first return stroke of an intense cloud-to-ground lightning flash was obtained by a slit-free spectrograph. Applying the atomic structure theory to the research work on lightning spectra, the wavelengths, oscillator strengths and excitation energies of upper levels were calculated for the transitions of related lightning spectrum. Multi-configuration Dirac-Fock method was employed in the calculation. From the results, re-identifications were carried out for the lines of 419.0 and 425.3 nm. It was found by spectral analysis combined with corresponding electrical information finds that the spectrum characteristic is closely related to the intensity of lightning discharge, as during an intense lightning return stroke the lines of O II with high excitation energies are enhanced.

English Abstract↗
PubMed1981

Experimental studies on the effect of artificial respiration after lightning accidents.

Many suggestions have been made regarding protective methods against lightning, without any quantitative tests of safety. As a fundamental study on lightning protection, the lethal threshold energy for the artificial lightning impulse was investigated, using 14 rabbits. The voltage and current impulse had a 1 microsecond wave front and 40 microsecond wave tail. The imposed energy was measured by simultaneous photographic recording of both voltage and current waves on separate oscilloscopes. The impulse voltage was applied to head, neck, upper chest, and lower chest while the right hind limb was grounded. Artificial lightning current impulses were fed through the skin of the animals by making the surface flash over so that the surface flash was monitored carefully to delete the data of this case which gives an erroneous energy value from the statistical analysis. The lethal threshold energy was found to be 157.6 +/- 54.1 Joule (J), and the percentage of survival was 25% when 160 J impulse energy was given. Impulses of 160 J were then applied to the heads of 21 other rabbits maintained on an artificial respirator. Under these conditions the percentage of survival increased significantly to 47.6%.

Animals↗
PubMedDate not supplied

Childhood lightning injuries on the playing field.

Two young boys were struck by lightning during summer outdoor activities. One of them died. A literature review reveals that the most commonly reported locations of childhood lightning injuries are on the playing field, at the swimming pool, and in tents. Knowledge of measures to lower the risks of lightning strikes as well as the use of new lightning detection technology should help to reduce the numbers of these tragic events in the future.

Adolescent↗
PubMed2002

Abnormal electroretinogram and abnormal electrooculogram after lightning-induced ocular injury.

PURPOSE: To report a case of abnormal electrooculogram and abnormal electroretinogram after lightning-induced ocular injury. DESIGN: Interventional case report. METHODS: A 39-year-old man was struck on the left forehead by a bolt of lightning. After resuscitation, he regained consciousness. RESULTS: Ophthalmic examination disclosed a best-corrected visual acuity of right eye (RE): 20/25 and left eye (LE): 20/50, burned eyelashes, punctate keratitis, iridocyclitis, anterior subcapsular lens opacity, missing foveolar reflex, and macular pigment epithelial defect LE. Fluorescein angiography revealed only an area of punctate leaking in the left eye. Electrooculogram showed reduced amplitudes, in the left eye. Arden ratio was RE: 2.04 and LE: 1.52. The amplitudes of scotopic and photopic electroretinogram b-waves were reduced in the left eye. After uneventful cataract surgery in the left eye, the follow-up electrooculogram and electroretinogram still showed reduced amplitude in the left eye. CONCLUSION: Lightning is an uncommon cause of ocular injury. This is the first report of abnormal electro-oculogram and abnormal electroretinogram after lightning-induced ocular injury.

Adult↗
PubMed2001

Production of nitrogen oxides by lightning and coronae discharges in simulated early Earth, Venus and Mars environments.

We present measurements for the production of nitrogen oxides (NO and N2O) in CO2-N2 mixtures that simulate different stages of the evolution of the atmospheres of the Earth, Venus and Mars. The nitrogen fixation rates by two different types of electrical discharges, namely lightning and coronae, were studied over a wide range in CO2 and N2 mixing ratios. Nitric oxide (NO) is formed with a maximum energy yield estimated to be ~1.3 x 10(16) molecule J-1 at 80% CO2 and ~1.3 x 10(14) molecule J-1 at 50% CO2 for lightning and coronae discharges, respectively. Nitrous oxide (N2O) is only formed by coronae discharge with a maximum energy yield estimated to be ~1.2 x 10(13) molecule J-1 at 50% CO2. The pronounced difference in NO production in lightning and coronae discharges and the lack of formation of N2O in lightning indicate that the physics and chemistry involved in nitrogen fixation differs substantially in these two forms of electric energy.

Atmosphere↗
PubMed1993

Acoustic effects of lightning.

The effects of lightning on the audiovestibular apparatus vary with the degree of injury. This depends on whether the individual is struck directly or indirectly by lightning. We reported two cases where lightning has caused trauma to audiovestibular apparatus and have reviewed the available literature. One patient was struck directly by lightning leading to rupture of the tympanic membrane and a conductive hearing loss. The other patient was struck indirectly via telephone cable and had a mixed hearing loss with tympanic membrane intact.

Age of Onset↗
PubMed1995

Neuropathology of lightning-strike injuries.

When a person is struck by lightning a spectrum of neurologic damage can result. Approximately one third of the strikes prove to be fatal. The possibility of damage to the CNS relates to the type of lightning injury (direct strike, stride potential, or side flash), the intensity and duration of the current, the pathway of the current within the body, and secondary injuries to brain either from cardiac arrest and hypoxia or from physical trauma. Direct strikes to the head have a high degree of fatality and often result in petechiae or larger brain hemorrhages. Although there may be some predilection for the petechiae to occur in the brainstem, the larger hemorrhages may be particularly located near the pathway of the electrical current and result from direct damage to brain vasculature. Enlarged perivascular spaces seen histologically are relatively subtle; they have been attributed to the effects of gas bubbles from electrolysis, heat formation, or both. Small vessel thrombi and neuronal changes may be present nearby. Some brain tissue softening and edema may be direct effects of passage of current. Often, however, hypoxic encephalopathy and cerebral edema occur following cardiopulmonary arrest when the passage of the current through the body presumably generates cardiac arrhythmias. Considerably less is known about the spinal cord injuries in lightning strike, although one detailed recent study suggests that demyelination may be an underlying mechanism. Similarly, myelin damage appears to be a feature of electrical and possibly lightning injury to the peripheral nervous system.

Brain Injuries↗
PubMed2003

Electron paramagnetic resonance spectroscopic evidence of increased free radical generation and selective damage to skeletal muscle following lightning injury.

The present case study examined changes in peripheral markers of free radical metabolism and skeletal/myocardial muscle damage 30 h after a mountaineer had survived a lightning storm, having experienced contact with what was considered to be "upward leaders" at 4200 m. Sea-level control data were available between 3 and 8 weeks prior to the altitude sojourn for comparative purposes. Follow-up measurements were obtained for the same individual 3 weeks following the incident after simulated exposure to the combined stresses of inspiratory hypoxia and physical exercise. Venous blood was assayed for molecular markers of skeletal [myoglobin and total creatine phosphokinase (CPK)] and myocardial [cardiac troponin I (cTnI)] muscle damage. Ex-vivo spin trapping with alpha-phenyl-tert-butylnitrone (PBN) combined with electron paramagnetic resonance (EPR) spectroscopy was incorporated for the direct detection of free radicals. The relative increases [post-exposure/preexposure x 100 (%)] in the concentration of the PBN adduct, myoglobin, and CPK in the "lightning blood" were markedly greater than those observed following the simulation study (PBN: 276 vs. 129%; CPK: 1130 vs. 182%; myoglobin: 205 vs. 115%). In contrast, no changes were observed for cTnI. A marked decrease in the PBN adduct, myoglobin, and CPK was observed within 2 h of completing the simulation study, following oral administration of water and lipid-soluble antioxidant vitamins in normoxia. These findings are the first to document lightning-induced free radical generation and selective damage to skeletal muscle in a high altitude mountaineer. Furthermore, free radicals may contribute to the pathogenesis of lightning injury, and dietary supplementation with antioxidant vitamins may prove of some benefit against associated tissue damage.

Adult↗
PubMed1990

An epidemiological description of lightning-related deaths in the United States.

To better quantify and update the health impact of lightning and to compare potential sources of information, we reviewed data from the National Centre for Health Statistics (NCHS) database for 1968 through 1985 and from the North Carolina Medical Examiner (NCME) computerized database for 1972 through 1984. We epidemiologically characterized all lightning-related deaths identified in these databases. Results of our analysis are presented together with previously published information from the National Oceanic and Atmospheric Administration and from the National Institute for Occupational Safety and Health. In the US, Wyoming has the highest average annual lightning-related death rate (0.196/100,000), whereas Florida has the largest cumulative incidence of deaths (200) for this 18-year period. Death rates are the highest for males and for people 10-19 years old. There is a tendency toward a slight, but steady, decrease in the yearly incidence of lightning-related deaths. One-third of the fatalities are job-related. Both the NCHS and NCME databases are limited in describing the circumstances and aetiologies of these deaths.

Adolescent↗
PubMed1989

Telephone-mediated lightning injury: an Australian survey.

Each year in Australia, about 60 people report injuries attributable to lightning surges while using a telephone during nearby thunderstorms. This paper presents information about such incidents and describes a retrospective survey of more than 300 telephone users reporting injuries possibly attributable to lightning. Questionnaires yielded 132 usable responses, and the results were analysed to identify the extent and nature of the lightning injuries. These are compared with direct strike injuries. Three distinct telephone-mediated lightning strike syndromes are identified (statistically) among the victims.

Australia↗
PubMed2002

Recently reported sightings of ball lightning: observations collected by correspondence and Russian and Ukrainian sightings.

The observations in the first section of this paper were sent to John Abrahamson in response to the publication of a recent paper on ball lightning, with the correspondents either reading the original paper, or reports of it in popular science articles. A selection of the cases has been made, including those which showed interesting detail possibly useful in debating ball lightning mechanisms. Any inserted text within parenthesis is the observer's response to follow-up queries from J.A. The age of the observer (where noted) is that at the time of the observation. Three observations (1 q-s) did not show motion independent of their surroundings, but have been included because of their other similarities to ball lightning. It is interesting to note the high proportion (greater than 0.5) of scientifically or technically trained observers in this collection. The data presented in the second section of this paper come from both letters and interviews. Our interview questionnaire consisted of 46 questions and was mostly carried out in quiet conditions. Observations in 2 a, e, h, l, m, q-t were corrected during several (two or three) interviews. Heading each observation case we note the most unusual property of the object. Ball lightning appears in Russia and the Ukraine usually in summer (June-August), and more rarely in spring (March-May), or autumn (September-November). It appears usually during the daytime, 13:00-17:00 h, when most summer thunderstorms take place. Observers in their descriptions usually use the term "morning" to describe the period from 06:00 to 11:00 h, "daytime" for 12:00-18:00 h, and "evening" for 19:00-21:00 h. The term "time' means the local time, and sometimes it is difficult to compare it with the local geographic time due to frequent official state summer-winter time changes. The decree time in Russia can in general differ from the geographic time by 1-2 h.

Female↗
PubMed2002

A fifth mechanism of lightning injury.

The four classic electrical mechanisms of lightning injury cannot account for all injuries. A fifth mechanism, injury by a weak upward streamer that does not become part of a completed lightning channel, has long been postulated in the engineering literature by lightning researchers. This paper reports a case of death where injury from a weak upward streamer is strongly suspected following forensic investigation. Neither high voltage nor any of the previously accepted mechanisms of lightning injury can explain this incident.

Diagnosis, Differential↗
PubMed2004

Lightning: an unusual cause of cerebellar infarction.

The neurological complications of lightning injury are not infrequent. However, scarce data are available on cerebellar infarction attributable to lightning injury. A 45 year old man was admitted to the emergency department because of lightning injury. The patient had a Glasgow coma scale score of 13/15 on arrival at hospital with accompanying dysarthria and hypotonia. Computed tomography of the head showed only a mild cerebral oedema. Ataxia was recorded on the fourth day. Magnetic resonance imaging of the head showed ischaemia predominantly in the cerebellar hemispheres bilaterally and in the parietal, temporal, and frontal lobes on the right. Anti-oedema treatment was started. The patient was discharged after seven days. After one month the patient was re-examined and found to have minimal ataxia and dysarthria. Lightning injury should not be overlooked in the aetiology and differential diagnosis of acute cerebellar ischaemic insult and relevant clinical findings in adults.

Brain Infarction↗
PubMed2001

Ear injuries caused by lightning: report of 18 cases.

The clinical management and long-term outcome in lightning survivors with substantial ear damage treated at the Department of Otorhinolaryngology, University Hospital Split during the 1984-1999 period are reviewed. Results of clinical management and outcomes of lightning ear damage in 18 patients (mean age 35.3 +/- 5 years) were retrospectively analyzed. On admission, all patients complained of severe pain, tinnitus and hearing impairment. Otomicroscopy revealed tympanic membrane rupture in 12 patients. The active therapeutic approach included immediate otomicroscopy, aseptic aspiration toilet, and eversion of perforation edges. In all patients, the ruptures healed well, and restitution of the hearing function was achieved. Follow-up examination performed in 1999 (13.2 +/- 2.9 years later) in 11 patients (mean age 52.3 +/- 6.1 years) revealed an almost identical audiogram as on discharge from the hospital, however, neuropsychological testing revealed numerous sequelae. Tympanic injury caused by lightning should be actively treated. Lightning survivors require additional psychotherapeutic treatment.

Adult↗
PubMedDate not supplied

Telephone-related lightning injury.

OBJECTIVE: To review reported telephone-related lightning injuries, outline the mechanisms of injury and suggest treatment strategies. DATA SOURCES: Cases notified to Telecom Australia and an extensive search of the literature. DATA SYNTHESIS: There is a dearth of literature on telephone-related lightning injury. Some reports note it in passing, others describe single incidents. Case reports from Australia provide detail sufficient for review, and the general principles which govern management of such injuries are presented. CONCLUSION: Telephone-related lightning injury is not rare. Practitioners should be aware of the uniqueness of lightning injury and the complexity of its assessment. A research program aimed at further elucidation of the detail of this injury is proceeding.

Australia↗