High levels of pollution in the Yamuna has been a cause for concern. With the latest research showing the presence of heavy metals in the river, water environmentalists have demanded creation of more data linking possible health impact due to contamination of food crops and adoption of better technology for suitable remediation to make the river healthy.
According to results of a study released here on Friday by Toxics Link, an environmental research and advocacy organisation, the river water clearly indicated the presence of heavy metals.
The test results show high level of heavy metals in the sediments of the Yamuna. The results also indicate the high variation in the concentration of heavy metals in the river water before and after Wazirabad.
Samples after Wazirabad more contaminated
The detection of high level of heavy metals in the samples after Wazirabad may be due to the discharge of waste water into the river from various canals and drains. So the vegetables grown in the Yamuna floodplains may have high levels of contamination, warns the study.
“All the detected heavy metals – lead, cadmium, chromium, mercury and arsenic – are known to cause serious health implications, so standards have been prescribed to limit the heavy metals content in drinking water and food,” noted the study.
The study tested the “Toxicity Load of Yamuna River in Delhi” and examined the pH, turbidity, solids, and heavy metals in water and sediments of the river. The samples were collected from different locations in Delhi (before and after Wazirabad) during pre and post monsoon season.
“The results indicate high concentration of turbidity and total solids at both before and after Wazirabad locations,” the study indicated.
Samples collected at all locations during pre-monsoon season show that the average turbidity level is 20 NTU and for total solids it is 687 mg/l (milligram per litre) in water. The Indian standard turbidity is 5 NTU, and the Indian standard for total solids is 500 mg/l in water.
During the post monsoon season, the average turbidity level is 27 NTU and total solid concentration is 810 mg/l. The pH level during both pre and post monsoon season was 7.03 and 7.11. The Indian standard for pH is 6.5 to 8.5 in water samples.
This study found high level of heavy metal contamination after Wazirabad in comparison to the samples collected before Wazribad, which is a serious concern.
“Lead, cadmium, chromium contamination was found in the river water. Also, mercury was detected in all the sediments samples… The average mercury concentration in pre and post monsoon season was 0.94 ppm and 3.95 ppm respectively,” noted the study.
Arsenic was also detected in all the sediments samples. The average arsenic concentration in pre and post monsoon season was 3.30 ppm and 7.73 ppm respectively.
