About 10 percent of people struck by lightning actually die. In the United States, this amounts to about 60 people (taken over a 30-year average) a year; in Canada, about 10 people per year. So, we estimate lightning injures about 600 people in the USA and 100 in Canada each year.
Lightning delivers a massive pulse of electricity. It can kill or injure a nearby person, either:
Â• by striking her directly, causing gigantic currents to surge through the body; or
Â• by striking something connected to her, such as a pipe carrying water to her shower or a wire conducting electricity to an electrical appliance she is holding. She then completes the circuit to ground, and huge currents flow through her body.
Lightning kills, primarily, by interrupting the heart's rhythm. The heart stops, or perhaps beats erratically, and breathing may cease. The heart can start up on its own, but breathing does not. If no one is there to help the victim, the lack of oxygen and possible nerve damage can cause the heart to stop, permanently.
In addition to jumbling electrical signals controlling heart beat and breathing, lightning can cause currents to flow through the brain, firing and possibly permanently damaging synapses. "If brain damage is severe, coma may develop. Typically, the person awakens but does not remember what happened before the injury. The person may be confused, think slowly, and have difficulty concentrating and remembering recent events. Personality changes may occur," says the Merck Medical Manuals.
Thunder noise and rapidly expanding air often perforate a person's eardrums. Electrical current passing over a body can:
Â• damage eyes, including creating cataracts;
Â• injure the nervous system so both legs become temporarily paralyzed, blue and numb;
Â• burn skin with a feathering, branching pattern, consisting of pinpoint spots like a cigarette burn, or streaks where sweat has boiled into steam.
The safest place to be during a lightning storm is inside a large, enclosed building (like a house) but not touching anything that conducts electricity (water, pipes or wires, for example) or in an enclosed metal car (not a convertible) or truck with the windows rolled up.
The riskiest place is in open terrain; next riskiest is under a tree. Florida usually has the most lightning strikes and fatalities of the 50 states, though, in 2006, Colorado tied Florida for the number of fatalities (5).
What are the risks of being struck by lightning?
Each year, lightning strikes 600 people, on the average, in the United States. The U.S. Census Bureau estimates the population in 2007 to be about 300,000,000. So, the odds of lightning striking a person in a year is about 600 / 300,000,000
1 / 500,000 or 1 in 500 thousand, states meteorologist John Jensenius of the NOAA and the National Weather Service.
The probability of lightning striking us over an 80-year lifetime is about 1 in 6,000.
Over the past 30 years, lightning killed more people in the U.S. than tornadoes or hurricanes, says Jensenius.
Similarly, lightning strikes 100 Canadians each year. Canada's national statistical agency (Statistics Canada) estimates the Canadian population in 2008 to be about 33,000,000. So the odds of lightning striking a Canadian in a year is about one in 300 thousand and over an 80-year lifetime is about 1 in 4,000.
Asilimia 10 ya watu wanaogongwa na umeme hufa Katika Marekani, hii ni karibu watu 60 (kuchukuliwa juu ya wastani wa miaka 30) kwa mwaka; katika Canada, karibu watu 10 kwa mwaka. Kwa mfano, umeme huumiza watu 600 nchini Marekani na 100 nchini Canada kila mwaka. Umeme hutoa mnururisho mkubwa wa umeme. Inaweza kumuua au kumjeruhi mtu aliye karibu, ama kwa kumpiga moja kwa moja, na kusababisha mkondo mkubwa wa umeme kupitia mwili; au kwa kumpiga kitu kilichounganishwa naye, kama vile bomba linalobeba maji kwenye bafu yake au waya unaoongoza umeme kwenye kifaa cha umeme anachokishikilia. Kisha anakamilisha mzunguko huo hadi ardhini, na mikondo mikubwa hutiririka kupitia mwili wake. Umeme huua, hasa kwa kuvuruga mdundo wa moyo. Moyo huacha kupiga, au labda hupiga kwa njia isiyo ya kawaida, na kupumua kwaweza kukoma. Moyo waweza kuanzisha kazi kwa nguvu zake mwenyewe, lakini kupumua hakuwezi. Ikiwa hakuna mtu wa kumsaidia mhasiriwa, upungufu wa oksijeni na uwezekano wa kuharibiwa kwa neva unaweza kusababisha moyo usisimame kabisa. Mbali na kuharibu ishara za umeme zinazodhibiti mapigo ya moyo na kupumua, umeme unaweza kusababisha mkondo wa umeme kutiririka kupitia ubongo, na kuharibu na kuharibu synapses. "Ikiwa uharibifu wa ubongo ni mkubwa, huenda mtu akawa na ugonjwa wa kukosa fahamu. Kwa kawaida, mtu huyo huamka lakini hatakumbuka kilichotokea kabla ya jeraha hilo. Mtu huyo anaweza kuchanganyikiwa, kufikiri polepole, na kuwa na ugumu wa kukaza fikira na kukumbuka matukio ya hivi karibuni. Mabadiliko ya utu yaweza kutokea", yasema Merck Medical Manuals. Sauti ya ngurumo na hewa inayopanuka haraka mara nyingi hufumba matumbo ya sikio la mtu. Mtiririko wa umeme juu ya mwili unaweza: kuharibu macho, ikiwa ni pamoja na kuunda cataracts; kuharibu mfumo wa neva, hivyo miguu yote miwili inakuwa ya muda, bluu na numb; kuchoma ngozi na feathering, muundo wa matawi, unaojumuisha alama za alama kama moto wa sigareti, au mistari ambapo jasho limechemka kuwa mvuke. Mahali salama zaidi pa kuwa wakati wa dhoruba ya umeme ni ndani ya jengo kubwa lililofungwa (kama nyumba) lakini usiguse kitu chochote kinachoongoza umeme (kwa mfano maji, mabomba au waya) au katika gari la chuma lililofungwa (si kabriolet) au lori na madirisha yaliyofungwa. Mahali penye hatari zaidi ni katika eneo la wazi; mahali penye hatari zaidi ni chini ya mti. Florida ni jimbo la Marekani lenye idadi kubwa ya watu wanaouawa kutokana na umeme, na ni jimbo la Colorado ambalo lina idadi kubwa zaidi ya watu wanaouawa. Kuna hatari gani ya kupigwa na umeme? Kila mwaka umeme huangusha watu 600 nchini Marekani. Idara ya sensa ya Marekani ilikadiria idadi ya watu katika mwaka wa 2007 kuwa karibu 300,000,000. "Uwezekano wa umeme kumgonga mtu kwa mwaka ni 1 kati ya 500,000,"" anasema John Jensen, mtaalamu wa hali ya hewa wa shirika la NASA." Uwezekano wa umeme kutushambulia katika maisha yetu ya miaka 80 ni 1 kwa 6,000. Katika miaka 30 iliyopita, umeme umeua watu wengi zaidi kuliko vimbunga au vimbunga. Kwa mfano, kila mwaka umeme huangusha watu 100 nchini Kanada. Shirika la Takwimu la Canada (Statistics Canada) limekadiria idadi ya watu nchini humo kuwa karibu milioni 33. Uwezekano wa umeme kumgonga mtu mmoja nchini Canada ni 1 katika miaka 80 ya maisha yake.