In this context it is worth mentioning

These pollutants also promote highly reactive oxygen species (ROS) production (Matés et al., 2010), and depression of several ROS quenching systems (Ishida et al., 2009), with subsequent accumulation of toxic compounds in blood and tissues (Knerr et al., 2006). In physiological conditions, the antioxidant defense system, provided by enzymes and antioxidants, scavenges ROS thus limiting or preventing oxidative damage (Halliwell, 2012). The imbalance between ROS production and neutralizing capacity of antioxidant mechanisms may lead to oxidative stress (Cadenas and Davies, 2000 and Halliwell and Gutteridge, 2000), which is associated with modifications of physiological and metabolic functions (Halliwell and Gutteridge, 2000).