Secondary particles formed from the exhaust of vehicles using ethanol-gasoline blends increase the production of pulmonary and cardiac reactive oxygen species and induce pulmonary inflammation.
BACKGROUND
Ethanol vehicles release exhaust gases that contribute to the formation of secondary organic aerosols (SOA).


OBJECTIVE
To determine in vivo toxicity resulting from exposure to SOA derived from vehicles using different ethanol-gasoline blends (E0, E10, E22, E85W, E85S, E100).


METHODS
Exhaust emissions from vehicles using ethanol blends were delivered to a photochemical chamber and reacted to produce SOA. The aerosol samples were collected on filters, extracted, and dispersed in an aqueous solutions and intratracheally instilled into Sprague Dawley rats in doses of 700 μg/0.2 ml. After 45 min and 4 h pulmonary and cardiac chemiluminescence (CL) was measured to estimate the amount of reactive oxygen species (ROS) produced in the lungs and heart. Inflammation was measured by differential cell count in bronchoalveolar lavages (BAL).


RESULTS
Statistically and biologically significant differences in response to secondary particles from the different fuel formulations were detected. Compared to the control group, animals exposed to SOA from gasoline (E0) showed a significantly higher average CL in the lungs at 45 min. The highest CL averages in the heart were observed in the groups exposed to SOA from E10 and pure ethanol (E100) at 45 min. BAL of animals exposed to SOA from E0 and E85S had a significant increased number of macrophages at 45 min. BAL neutrophil count was increased in the groups exposed to E85S (45 min) and E0 (4 h). Animals exposed to E0 and E85W had increased BAL lymphocyte count compared to the control and the other exposed groups.


DISCUSSION
Our results suggest that SOA generated by gasoline (E0), followed by ethanol blends E85S and E85W, substantially induce oxidative stress measured by ROS generation and pulmonary inflammation measured by the recruitment of white blood cells in BAL.
['da Silva|Talita Dias|TD|', 'Barnabé|Viviani|V|', 'Ricci-Vitor|Ana Laura|AL|', 'Papapostolou|Vasileios|V|', 'Tagle|Matias|M|', 'Henriquez|Andres|A|', 'Lawrence|Joy|J|', 'Ferguson|Stephen|S|', 'Wolfson|J Mikhail|JM|', 'Koutrakis|Petros|P|', 'Oyola|Pedro|P|', 'Ferreira|Celso|C|', 'de Abreu|Luiz Carlos|LC|', 'Monteiro|Carlos Bandeira de Mello|CBM|', 'Godleski|John J|JJ|']
D000393:Air Pollutants D000818:Animals D000431:Ethanol D005742:Gasoline D006321:Heart D007958:Leukocyte Count D008168:Lung D008264:Macrophages D009504:Neutrophils D018384:Oxidative Stress D011014:Pneumonia D051381:Rats D017207:Rats, Sprague-Dawley D017382:Reactive Oxygen Species D001335:Vehicle Emissions
Inflammation Chemiluminescence Bronchoalveolar Bioethanol Particulate matter