ALHOL AND FATAL ROAD TRAFFIC ACCIDENTS; A REVIEW OF 500 CASES FROM NORTH & WEST LONDON 1970-79 T.M.T. Sheehan and D.A.LI. Bwen. Department f Frensic Medicine, Charing Crss Hspital Medical Schl, Lndn, England. Intrductin Despite 13 years f legislatin which impsed a legal limit n the amunt f alchl permitted in the bld f vehicle drivers, the incidence f rad traffic accidents (RTAs) invlving drinking drivers cntinued t be a prblem. This is reflected in the Gvernment's recent cnsultative dcument n drinking and driving which incrprated the findings f 2 the Transprt and Rad Research Labratry (TRRL). Mre recent cncern has been expressed in the medical press n the extent f the 3 prblem and at the delay in drafting further effective legislatin. It was thught that it might be f interest t analyse the recrds f the Department f Frensic Medicine ver the years 1070-79, in terms f alchl and its invlvement in fatal RTAs. The Catchment Area Invlved The new Charing Crss Hspital and Medical Schl has been situated in Hammersmith, West Lndn since 1973, the riginal building being in Central Lndn. The Department f Frensic Medicine perfrms pst mrtems at the request f H.M. Crners fr the varius districts f Nrth and West Lndn. Thus, the fllwing review is based upn 834 RTA pst mrtems (PMs) carried ut at 15 mrtuaries in the area. This area cmbines residential districts and a large part f Lndn's majr traffic system i.e. the Nrth Circular Rad jining the M4 and M40 mtrv/ays (t Wales and the West) and the Ml (t the Nrth). Peak cmmutr traffic is als heavy thrughut the area. The catchment area was nt altered materially when the hspital 180
mved frm Central t West Lndn. Sample Size and Distributin During the 10 years 1970-79 PMs were perfrmed n 834 victims f RTAs. These are listed in Table 1: Table 1 R.T.A. PMs 1970-79 : CATEGORIES & ( Ttal Pedestrians 217 217 434 M/V Drivers 139 14 153 M/V Passengers 56 44 100 M/C Riders 89 5 94 M/C Passengers 9 6 15 Pedal Cyclists 33 5 38 543 291 834 It will be nticed that the ttal when brken dwn prduces categry sample sizes that are nt large by statistical standards. Further sub-divisin f each categry yields annual ttals which may be said t be statistically small, and therefre subject t randm variatin. Thus, it was felt that interpretatin f yearly fluctuatin especially when related t alchl invlvement had t be rather circumspect. Fr the same reasn, it was nt thught valid t make direct cmparisns between yearly ttals and natinal statistics fr the same year, e.g. fr 1976, the number f PMs n mtr vehicle drivers where alchl was measured was 12; the same figure fr England and 2 Wales was 570. Extent f Alchl Measurement There are certain circumstances in which bld alchl cncentratin (BAC) f an RTA victim is nt measured: 1. Age, the victim being accunted t yung t nrmally cnsume alchl. This was s in 8% f cases. A by f 9, and 7 cases between 13-15 had BACs measured which were negative,but in general BAC measurements were perfrmed n all victims f 16 years r ver (but see belw). 2. Time f Death. A prprtin f RTA victims wh die in hspital 181
may have cnsumed alchl prir t the accident, but if this time interval is greater than 12 hurs, BAC is nt measured, as any alchl present at the time f the accident will have been significantly metablised. In the present study this was the case in 31% f victims: Table 2 R.T.A. PMs : EXTENT f B.A.C. MEASUREMENT Pedestrians M/V Drivers M/V Passengers M/C Riders M/C Passengers Pedal Cyclists % Nt Measured % Measured Ttal Age Died After 12hrs 13 35 52 434 0 23 77 153 5 23 72 100 0 26 74 94 0 20 21 42 8 31 80 15 37 38 61 834 Ante Mrtem Bld Samples Rarely, a.m. hspital specimens taken n admissin are available. In the present study, this ccurred in 15 f the 513 cases where BAC was measured. In eight instances the BAC was negative. Values btained fr the remainder ranged frm 61 - * 353 mg%, the victims dying between 4 hurs and 5 weeks after the accident. The victim having an a.m. BAC f 353mg% died 3 hurs after admissin and the subsequent p.m. level was 72mg%. The large difference a.m. and p.m. values i.e. 281mg% in 3 hurs is prbably explained by the fact that the victim was transfused. Whilst a.m. bld samples are useful in assessing the alchlic state f a victim wh later dies, they are nt used as evidence 4 except in crner's curts. * This paper will use the British cnventin f mg. alchl/looml bld (mg%). Thus, the legal limit in Britain is 80mg% = 0.8pr mille =.08%. 182
RESULTS The results are presented under three headings; BAC invlvement, age and time f day when accidents ccurred. Summary tables f these parameters are appended. In the case f the BAC summary the sexes are distinguished; hwever, in the text nly verall figures will be presented where n great difference between male and female was bserved. Als appended are graphs illustrating yearly trends fr the majr victim categries. Thus, f the 834 victims examined, 513 (61%) were measured fr alchl. Of these, 38% had psitive BACs, 23% BACs >80mg% and 6% BACs >200mg%. 351 males were measured, 47% having psitive BACs, 30% BACs )>80mg% and 9% BACs ^>200mg%. Equivalent figures fr the 162 females measured were 20%, 7% and 1% respectively. Pedestrians Pst mrtem examinatin was made f an equal number f males and females (217 f each), and again almst equal numbers were measured fr BAC. BAC Of 114 males measured 38% had psitive BACs, 24% had BACs > 80mg% and 14% BACs 200mg%. The equivalent figures fr the 113 females measured were 13%, 3% and 0% respectively. Age 51% f males measured were between 51-80 years, 16% f this age range having BACs f BACs 80mg% was 41-60 years (53%). 80mg%. The age grup having the highest incidence Of females measured, 21% were ver the age f 80, and 72% ver 60 years, yet nne f these had BACs 80mg% Time f Day * 28% f accidents t males measured ccurred between 2200-0400, 24% in the fur hurs previus. In the later time perid 50% f victims had BACs )>80mg% while the figure between 1800-2200 was 24%. In Lndn, licensing laws allw drinking n public premises frm 1700-2230/2300. Thus^jurnies between 2200-0400 are after peak drinking. 183
In terras f all victims with BACs >80mg%, 52% had their accidents between 2200-0400, and 22% between 1800-2200. Accident t females were fairly well distributed between 0900 and 2200 hurs, the perid f greatest risk being 1600-1800 (22% f thse measured). Nne f the victims in this time perid had BACs > 80mg%, and nly ne was psitive. The three victims with BAC> 80rag% were in accidents between 2200-0400. Mtr Vehicle Drivers 153 PMs were perfrmed n mtr vehicle drivers (139 males and 14 females) and f these BAC measurements were made n 109 males and 9 females. BAC Overall, 56% f drivers measured had psitive BACs, 42% were y 80mg% and 9% y 200mg%. The highest BAC attained by a driver was 400mg% (urine 453mg%), by a 34 year ld male. Age In ttal, 51% f measured drivers were in the age grup 17-30 years, and f these, 58% had BACs/>80mg%. Further, this age range cntained 65% f all drivers with BACs 80mg%. Time f Day 47% f accidents invlving measured drivers ccurred between the hurs 2200-0400, 71% f the victims having BACs 80mg%. Of the ttal with BACs)>80mg%, 73% were invlved in accidents within this time perid. Mtr Vehicle Passengers 100 PMs (56 male, 44 female) were perfrmed n mtr vehicle passengers. Of these BAC measurements were made n 41 males and 31 females. BAC 51% f all passengers measured had psitive BACs, 25% had BAC / 80mg%, and 4%^200mg%. 49% f measured passengers were in the age grup 17-30, 25% f 184
these having BACs >80mg%. Cntained within this age range were 50% f all passengers with BACs >80mg%. Time f Day 50% f victims measured were invlved in accidents between 2200-0400, 40% f these having BACs )>80mg%. Of all passengers with BACs ^>80mg%, 75% are cntained within this time perid. Mtr Cycle Riders The term 'mtr cycle' is taken t cver scters and mpeds as well as the mre pwerful machine usually assciated with the term. Of the 89 male victims, 65 were measured, and all 5 f the females. BAC Nne f the females, three f whm were mped riders, had psitive BACs. Amngst the male victims (including 2 mped and 3 scter riders), 40% had psitive BACs, 22% had BACs)>80mg%, and 3%^200mg%. Hwever, these are figures fr the decade, and shuld be viewed in the yearly trends fr mtr cycle riders, as it is this victim categry that can with mst cnfidence be assigned a definite trend ver the years 1970-79. Thus, in the years 1970-74, 12 male victims were measured, 2 had psitive BACs, and nne was greater than 80mg%. The secnd five years, 1975-79, prduced 53 males measured, 24 f which (45%) had psitive BACs while 14 (26%) had BACs ^>80mg%. The highest BAC recrded fr a mtr cycle rider was 219mg% (urine 266mg%) by a 31 year ld male. Age 84% f accidents t mtr cycle riders invlved victims between 16-30, althugh nly 18% f the grup had BACs > 80mg%. Of thse with BACs^>80mg%, 79% were aged 16-30. Fr the years 1970-74 the mean age f the victims measured was 19, nne having BACs)>80mg%. Hwever, fr 1975-79 this had risen t 27, but mean age fr victims with BACs >80mg% in the high risk age grup was 2 1. 185
Time f Day Fr thse measured, accidents t mtr cyclists were fairly well distributed thrughut the day. Thus, the highest incidence ccurring between 2200-0400 was 32%, when 46% f victims within this time perid had BACs ^>80mg%. Cntained in it als were 50% f accidents t victims with BACs^>80mg%. Other high risk perids were 1600-1800 and 1800-2200, with 19% and 2 2%, respectively f all measured accidents. Mtr Cycle Passengers PMs were carried ut n 9 males and 6 females, all the males and 3 f the females being measured fr alchl. BAC Of the twelve measured, 7 (58%) had psitive BACs, and 4 (33%) BACs ^80mg%. Age 10 (83%) f thse measured were between the ages f 16-30, this range cntaining 3 f the 4 victims with BACs^>80mg%. Time f Day 5 (42%) f the twelve measured victims were in accidents between 2200-0400, and f these 4 (80%) had BACs]>80mg%. This represented the ttal with this BAC. Pedal Cyclists PMs were perfrmed n 38 cyclists, 33 male and 5 female, BAC measurements being made n 13 males and ne female. BAC Only tw f the victims were fund t have psitive BACs, f magnitude 25mg% and 18mg% (males f 81 and 20 years respectively). Age Of the furteen measured, 8 (57%) were aged between 51-80, and 5 between 16-30. Time f Day Incidence f accidents was distributed evenly thrughut the day, the 'high risk' perid between 1600-1800 accunting fr 3 victims. 186
DISCUSSION Pedestrians It can be seen that accidents t female pedestrians, are attributable (in terms f the pedestrians respnsibility) mre t age than t alchl, while with males drinking appears t be a factr which cannt be ignred. Whether r nt a BAC f 80mg% is indicative f impairment in a pedestrian is a mt pint, althugh the figure is useful as an index f cmparisn. A mre statistically based figure has been suggested by Claytn et al frm their study f alchl and pedestrian accidents 5 in the West Midlands Metrplitan area. The BAC put frward was y 120mg%, this applying t 27% f males (ttal 194) and 7% f females (ttal 150) wh died within 12 hurs f accident. The equivalent figures in the present study were 20% f males (ttal 114) and 2% f females (ttal 113). Thus, pedestrians under the influence f alchl may cause r precipitate an accident - fatal r therwise. Hwever, there is n legislatin with regard t analysis f alchl in pedestrians invlved in accidents - a serius mmissin as they may be respnsible fr precipitating an accident where blame falls upn the mtrist. Mtr Vehicle Drivers The results fr mtr vehicle drivers are nt dissimilar frm the much quted findings f the TRRL reprts, and the gvernment's cnsultative dcument, and this in itself is nt unexpected. What is clear, is that the prblem, as seen by this department, is ne f the male drinking driver. Mtr Cyclists Fatalities t mtr cycle riders tend t be assciated with age, and age plus alchl, rather than alchl alne. Accidents amngst mtr cyclists have been n the increase since g 1974, the figures here tend t supprt this view. 187
Pedal Cyclists In the area encmpassed by the study the 'drinking cyclist' des nt appear t be a prblem, and indeed cyclists have nt cntributed greatly t the number f RTA fatalities. This is smewhat surprising, as in the experience f ne f the authrs (TMTS), cycling has, ver the last few years becme an increasingly ppular mde f transprt. It is perhaps wrthwhile pinting ut that while legislatin exists requiring a mtr vehicle driver t prvide a bld r urine sample when invlved in an RTA, n such legislatin exists with regard t fatal accident victims. The prcedure as perated is based upn cmmn sense and cnsensus t facilitate crners' investigatins. Cnclusin Established patterns f alchl invlvement are evident, i.e. f victims dying within twelve hurs f accident, 42% f drivers, 22% f mtr cycle riders had BACs ver the legal limit f 80mg%. Similarly, 20% f male, and 2% f female pedestrians culd be judged impaired, i.e. they had BACs ^120mg%. The 'drinking-driver' prblem is almst entirely related t males, within the ages 16-30. References 1. Dept, f transprt. Cnsultative Dcument n Drinking and Driving. Lndn, 1979. 2. Transprt & Rad Research Labratry. Supplementary Reprt 441(1978) 3. British Medical Jurnal.1980. 19th. January, Editrial. 4. Bwen, D.A.L1. Mdern Medicine, 1980. March, pp 67-69. 5. Transprt & Rad Research Labratry. Supplementary Reprt 332 (1977) 6. A Special Crrespndent. British Medical Jurnal. 1979, 1, 39-41. Acknwledgements Drs. U.K.D.A. Gnetilleke & R. Sarvesvaran, Frensic Med., C.X.H.M.S. Miss B. Sextn, fr her excellent typing. Medical Illustratins Dept., C.X.H. fr their help & curtesy. 188
YEARLY R.T.A. P.M.s: 1970-79 100 80 60 40 0 0-20 70 '71 72 73 174 75 76 77 78 79 a X N. f P.M.s perfrmed 0 % f P.M.s in which B.A.C. measured O -- % f thse measured in which B.A.C. psitive 189
R.T.A. P.M.s : YEARLY TREND -- N. f P.M.s where B.A.C. measured 0 -- N. f P.M.s where B.A.C. 80mg% 190
R.T.A. P.M.s : YEARLY TREND -- N. f P.M.s where B.A.C. measured O N. f P.M.s where B.A.C. J>80mg% 191
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