assessment on in-vehicle concentration of carbon monoxide for taxis in central business district of tehran

background and aim: carbon monoxide is colorless and odorless gas. in high concentrations, co is deadly poisonous and in low concentrations can cause fatigue, headache, dizziness and seizures. carbon monoxide has a high affinity to combines hemoglobin which can decrease oxygen capacity in blood. to address this problem, human body begins to produce red blood cells, this can increases blood viscosity and thus increase diseases such as stroke and heart attack. about 60 percent of total emissions of carbon monoxide are associated automobile exhaust. in this study, concentration of carbon monoxide has been measured in the cabin space of taxis in high-traffic areas of tehran. materials and methods: this study is carried out in spring and summer 2011. concentrations of carbon monoxide in different types of taxi cabin space (peugeot, samand, pride and peykan) were measured by carbon monoxide meter q rae 2 models in different conditions of motion: high speed (over 45 kilometers per hour), low speed (15-30 kilometers per hour) and stop (0 kilometers per hour). results: results showed that concentration of carbon monoxide in old vehicles (above 10 years) is more than three times compared to new vehicles and outdoor. in addition, according to the measured values, at low speeds, values of co rapidly increased, so that in speeds of less than 15 km, values of co go beyond standard values (9 ppm). conclusion: results show that the mean value ​​of the measured concentration of carbon monoxide is higher than amounts recommended by who and epa and local authorities such as air quality control organization of tehran. concentrations observed in this study are up to 40 more than results of a study by german researchers in summer 1995 and winter 1996. references zagury e, moullec y l, momas i. exposure of paris taxi driver to automobile air pollutants within their vehicles. j occup environ med 2000; 75 (6): 406 - 410. fondelli m, chellini c, yli-tuomi et. fine particle concentrations in buses and taxis in florence, italy. atmos environ 2008; 42 (35): 8185-93. chan ly, lau wl. exposure level of carbon monoxide and respirable suspended particulate in public transportation modes while commuting in urban area of guangzhou. china atmosph environ 2002; 36 (28): 5831-40. adrian a, fernandez-bremauntz m, ashmore r. exposure of commuters to carbon monoxide in mexico city—i. measurement of in-vehicle concentrations. atmos environ 1995; 29 (4): 525-532. an sh, hu x, wang j. urban taxis and air pollution: a case study in harbin, china. j transp geog 2011; 19 (4): 960-7. chan ly, liu ym. carbon monoxide levels in popular passenger commuting modes traversing major commuting routes in hong kong. atmos environ 2001; 35 (15): 2637-46. riediker m, williams r, devlin r, griggs t, bromberg p h. exposure to particulate matter, volatile organic compounds, and other air pollutants inside patrol cars. www.http://pubs.acs.org/doi/abs/10.1021/es026264y. access date: nov. 2012.