Mains Paper 3: Environment | Conservation, environmental pollution and degradation, environmental impact assessment
From UPSC perspective, the following things are important:
Prelims level: Biomarkers
Mains level: Utility of biomarkers in pollution assessment
- Honey from urban areas can be used as biomarker to identify polluted localities, according to a study conducted by Pacific Centre for Isotopic and Geochemical research (PCIGR).
What is a Biomarker?
- A Biomarker is defined as a change in biological response, ranging from molecular through cellular and physiological responses to behavioral changes, which can be related to exposure to or toxic effects of environmental chemicals.
Honey as bio-marker
- The honey samples, analysed for the study, were collected from six geographical areas within Vancouver, including urban, industrial, residential and agricultural.
- From these samples, the scientists tested for three major elements — Lead, Zinc, Copper.
- The results showed that areas with heavy vehicle movement and industrial activity had increased concentration of lead in honey.
- On the other hand, samples from agricultural land indicated high levels of manganese, which researchers suspect could be because of pesticide use.
- Since the honey bee collects nectar from within a range of three to four kilometers, it is easy to point the source for its contamination.
- Similarly, another study of the aquatic plant called water hyacinth, or Eichhornia crassipes, found that these can be used as biomarkers.
- This plant is commonly found in tropical countries and is known for its ability to absorb nutrients and other elements from water.
- The stems and leaves, have been successfully used as indicators of heavy metal pollution in tropical countries.
- The uptake of heavy metals in this plant is stronger in the roots than in the floating shoots, states the study.