Emerging contaminants are of great concern because they are ubiquitous in the environment. They are constituents of building materials, creams, fragrances, toiletries. They have been reported of getting into tissues of biota globally. This review aims at creating awareness about the presence of these contaminants and their potential to adversely impact the man and other organisms on the earth surface.
Humankind, in the course of making life more conducive keeps exploring resources. The exploration keeps generating different pollutants which have potential to adversely impact on the environment. Emergent contaminants are toxicants that have not been regulated by law in their discharge to the environment. Some of these substances are totally new while others have been in use but their toxicity have not been studied. These chemicals are of concern globally because they are now ubiquitous and they get into aquatic environment and the food chain.
CATEGORIES OF EMERGING CONTAMINANTS, OCCURRENCE IN THE ENVIRONMENT.
Emerging pollutants are of different categories. They range from pharmaceuticals, personal care products, flame retardants, perfluoroalkyl substances to mention a few. These substances are used on day to day basis and they constitute a thing of concern because of their rate of entry into the environment.
Pharmaceuticals these days ranges from pain killers, anti-depressants, antibiotics, veterinary drugs and so on. Their prevalence is due to usage in curing and preventing of different types of diseases. They are present in human waste such as urine and feaces. Other sources include the waste water plants from manufacturing sites and hospitals. They get into the environment when these stored wastes are discharged into surface water and also when animal waste are used for compost on agricultural lands. These substances are recalcitrant as such they stay longer in the environment.
- Personal Care Products
Personal care products include toiletries, fragrance, creams, and disinfectants. These substances can be classified into three (3), polycyclic musk, parabens and triclosan. These substances enter into the environment through effluents from activities such as washing of hair, clothes and bathing discharged into sewage treatment plant. It can also be washed into recreational pools during swimming activities.
- Flame Retardants
Flame retardants are components of textiles, furniture, building materials and furnishing foams in computers, televisions. These substances make these materials less inflammable. They are similar to group of environmental pollutants called polychlorinated biphenyls. Brominated flame retardant has been banned due to their persistence in the environment. Other group in use are the organophosphate flame retardant. Though this are less persistent but their presence in the environment has been documented. They also enter into the environment through discharge of effluent into water bodies.
The spread of these substances is attributed to the fact that they are daily consumptions. There have been several documentations of their presence in the surface water, underground water, soils. These are also getting into the food chain through uptake by aquatic organisms and vegetative part of plants. For instance, Ziarrusta et al reported the accumulation of musk fragrance in marine mollusks from Columbia and Nicaragua. Also, Boxal et al documented veterinary medicines and their metabolites are directly release in the soil when manure is applied to agricultural land. Asides building up in food chain, the presence of these contaminants are already causing loss of biodiversity. Lemus et al state that residue of s certain antibiotics has been detected in eggs of vulture and red kites. This is said to cause fatal embryo chondral, the implication of this is that the number of these organisms would diminish if reproduction is threatened and as such result in their extinction.
It is evident that these categories of pollutants are present in all environmental matrices. It is important to point out that some parts of the world are aware of the toxic potentials of these substances, and their use are being discouraged, while some parts are still ignorant of the presence of the substances. Hence in parts of the world where the latter is the case, awareness should be intensified to ensure the populace are well informed. These substances should be banned totally if less toxic alternatives are available.
- Ziarrusta, H., Olivares, M., Delgado, A., Posada-Ureta, O., Zuloaga, O., and Etxebarria, N. (2015). Multi-screening Determination of Organic Pollutants in Mollusks Using Matrix Solid Phase Dispersions. Journal of Chromatoghraphy A 1391:18-30
- Boxall, A. B., Fogg, L. A., Kay, P., Blackwell, P. A., Pemberton, E. J., and Oxford, A.
(2004a). Veterinary Medicines in the Environment. Rev. Environmental Contamination T. 180: 1-91
- Lemus, J. A., Blanco, G., Arroyo, B., Martinez, F., and Grande, J. (2009) Fatal Embryo
Chondral Damage Associated with Fluoroquinolones in Eggs of Threatened Avian Scavengers. Environmental Pollution. 157(8-9): 2421-2427