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�pectrum Laboratories Chemical Fact Sheet-Cas#73432 http l/www speclab com/compound/c92527
<br /> tank with a wind speed of 7 09 m/sec was 5 23 hrs ,the estimated half-life for
<br /> volatilization of benzene from a model river one meter deep flowing I msec with a
<br /> !wind velocity of 3 msec is estimated to be 2 7 hrs at 20 deg C It will not be
<br /> !expected to significantly adsorb to sediment,bioconcentrate in aquatic organisms or
<br /> hydrolyze It may be subject to biodegradation based on a reported biodegradation
<br /> half-life of 16 days in an aerobic river die-away test In a marine ecosystem,
<br /> !in
<br /> occurred m 2 days after an acclimation period of 2 days and 2 weeks
<br /> Environmental Fate !in the summer and spring,respectively,whereas no degradation occurred in winter
<br /> AQUATIC FATE Evaporation was the primary loss mechanism in winter in a
<br /> mesocosin experiment which simulated a northern bay where the half-life was 13 i
<br /> i days In spring and summer the half-lives were 23 and 3 1 days,respectively In !
<br /> these cases biodegradation plays a major role and takes about 2 days However,
<br /> } acclimation is critical and this takes much longer in the colder water in spring
<br /> I !According to one experiment,benzene has a half-life of 17 days due to
<br /> Iphotegradation which could contribute to benzene's removal In situations of cold
<br /> 'water,poor nutrients,or other conditions less conducive to microbial,photolysis
<br /> j will play a important role in degradation ATMOSPHERIC FATE If benzene is !
<br /> released to the atmosphere,it will exist predominantly in the vapor phase
<br /> Gas-phase benzene will not be subject to direct photolysis but it will react with
<br /> 1photmbemically produced hydroxyl radicals with a half-life of 13 4 days calculated
<br /> lusing an experimental rate constant for the reaction The reaction time in polluted
<br /> atinospheres which contain nitrogen oxides or sulfur dioxide is accelerated with the
<br /> {half-life being reported as 4-6 hours Products ofphotooxidation include phenol, }
<br /> E �nitrophenols,nitrobenzene, formic acid,and peroxyacetyl nitrate Benzene is fairly j
<br /> I !soluble in water and is removed from the atmosphere in rain
<br /> DRINKING WATER 113 public supplies, 1976, 7 sites pos,avg of positive sites�—
<br /> { <0 2 ppb 5 USA cities, 1974-5,0-0 3 ppb Contaminated drinking water wells in
<br /> II
<br /> ANY,NJ,CT, 30-300 ppb,highest concn in drinking water from surface source,4 4 I
<br /> } ppb 3 surveys of community water supplies 0 of I I 1 pos, 7 of 113 pos,mean 4
<br /> Mppb,4 of 16 pos (0 95 ppb-max) USA Groundwater Supply Survey(GWS, 1982,
<br /> finished drinking water),466 samples selected at random from 1000 in survey, !
<br /> } 0 6%pos,3 ppb median, 15 ppb max Wisconsin drinking water wells,data
<br /> } 1d rough Jun 1984, 1174 community wells,0 34%pos, 617 private wells,2 9%
<br /> Ipos(6) GROUNDWATER Chalk Aquifer(UK),210 m from petrol storage, 1-10
<br /> } ppb,Chalk Aquifer(UK), 120 m from petrol storage,>250 ppb,Chalk Aquifer
<br /> I(UK), 10 m from petrol storage, 1250 ppb,distances refer to benzene movement in
<br /> ' ;groundwater SURFACE WATER 14 heavily industrialized with basins,
<br /> 11975-1976,20%samples>1 ppb and between I and 7 ppb Lake Erie, 1975-6,0-1
<br /> ppb, 1 of 2 sites positive, Lake Michigan, 1975-6,0-7 ppb,5 of 7 sites positive
<br /> '
<br /> 1700 random sites in US, 1975, 5 4 ppb avg US EPA STORET database, 1,271 !
<br /> !samples, 15 0%pos, 5 0 ppb median SEAWATER 5-15 parts per trillion Gulf of
<br /> !Mexico, 1977,unpolluted areas,5-175 parts per trillion, Gulf of Mexico, 1977,
<br /> !anthropogenic influence RAIN/SNOW Detected m rainwater to Japan and in the !
<br /> ' !UK(87 2 ppb)(1,2) Benzene occurs in both ground water and surface public water
<br /> t Isupplies with higher levels occurring in ground water supplies Based upon Federal
<br /> j (drinking water surveys,approximately 13%of all ground water systenis are j
<br /> estimated to contain,benzene at levels greater than 0 5 ug/1 The highest level i
<br /> ' Ireported in the surveys for ground water was 80 ug/1 Approximately 3%of all
<br /> Isurface water system are estimated to be contaminated at levels higher than 0 5 ug/l {
<br /> !None of the systems are expected to contain levels higher than 5 ug/1 EFFL I
<br /> ,Wastewater from coal preparation plants,0 3-48 ppb ,wastewater from plants which I
<br /> {manufacture or use benzene<1-179 parts per trillion,stack emissions from coking
<br /> !plants (Czechoslovakia), 15-50 ppm ,stack emission estimates from chemical plants
<br /> 3using emissions and worst case modeling at 150 in from source, less than or equal to!
<br /> ' Drinkmg Water Impact ;5 ppm Groundwater at 178 CERCLA hazardous waste sites, 11 2%pos US EPA I
<br /> 1STORET database, 1,474 samples, 16 4%pos, 2 50 ppb median Industries in
<br /> } !which mean or max levels in raw wastewater exceeded 1 ppm are(number of
<br /> samples,percent pos,mean,max, in ppm) raw wastewater auto and other laundries j
<br /> I(20 samples, 70%pos,<1 4 ppm mean,23 ppm max),iron and steal manufacturing
<br /> 1(mfg)(9 samples,77 8% pos,<8 0 mean,46 max),aluminum forming(32 samples, I
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