Air pollution effects on the activity of antioxidant enzymes in nerium oleander and robinia pseudo acacia plants in Tehran
Air pollution is one of the most significant environmental concerns in both developed and developing cities. The urban air quality is continuously affected by emissions from both stationary and mobile combustion sources. Mobile sources contribute to the emission of major urban air pollutants including: carbon monoxide (CO), nitrogen oxides (NOx), sulphur oxides (SOx), particulate matter (PM), lead (Pb), photochemical oxidants such as ozone (O3) and ozone precursors like hydrocarbons and volatile organic compounds (Costa, 2001). Various physical, chemical and dynamic processes may generate air pollutants including particulates and gaseous contaminants that may cause adverse health effects in human or animals, affect plant life and impact the global environment by changing the atmosphere of the earth (Raabe, 1999; Bakand et al., 2005; Hayes et al., 2007). While plants can improve the air quality in some extent, air pollution may adversely influence the plant life. Air pollutants such as ozone may inter into plant tissues via stomata and elevate the level of reactive oxygen species (ROS) causing serious damage to the DNA, proteins and lipids (Sharma and Davis, 1994; Hippeli and Elstner, 1996).