Chemical additives, damaging effects

Central nervous system injury is a common effect associated with exposure to vapors of chlorobenzene in humans. Studies in animals suggest that chlorobenzene can also result in damage to the liver and kidneys. Since similar effects occur with exposure to other chemicals, additional studies are needed to identify more specific biomarkers by which to monitor populations living near hazardous waste sites. 

Considering the mechanical stress loads acting upon the plastic in addition to the attacking medium, it is apparent that they would further exacerbate the damaging effects. Therefore, the chemical resistance of different plastics, a factor that must be known for pipelines in particular, can be determined in time tests. 

With the development of oil industry, the general environment and in particular wetland ecosystem has become extremely vulnerable to damaging effects of oil pollution. Contamination of aquatic environment by crude oil and petroleum products constitute an additional source of stress to aquatic organisms (Omoregie et ah, 1997) and is of importance to the wetland environment. Oil contaminated water resulted in water becoming unsuitable for the growth of macrophytes (Edema, 2006) only scanty data are available for levels of chemical pollution of aquatic plants since most studies of biota are concentrated in fish (FAO, 1993). 

---