|Pollution from industrial revolution, Europe in the Himalayas. theprint.in|
|soot pollution from industry. wired.com|
An analysis of ice cores drilled from the Dasuopu glacier in the central Himalayas shows traces of toxic metals, by-products of burning coal, embedded in the sample’s layers. By sifting the timeline of the ice core, the researchers have dated the earliest contamination to the end of the 18th century - the start of the Industrial Revolution.
The results of the study were published in Proceedings of the National Academy of Sciences. The team from Ohio State University, USA studied an ice core collected in 1997 from the glacier located on Shishapangma, the world’s 14th tallest mountain. Surprisingly core samples revealed the hidden clues about the snowfall, atmospheric circulation, and other environmental changes in time. The detailed analysis of layers in the core helped the researchers to arrive at the past event and its time with considerable accuracy. The layers in the ice core appeared to have been formed between 1499 and 1992. They also found a total of 23 trace metals whose concentration was higher-than-natural levels of cadmium, chromium, nickel, and zinc during the period from 1780. When they traced the bottom of the source and the period they arrived at the conclusion that the contamination was caused by the burning of coal –an important energy source in the European industry during the late 18th century, and throughout the 19th and 20th centuries.
According to Paolo Gabrielli, lead author of the study and research scientist at The Ohio State University Byrd Polar and Climate Research Center, “ the Industrial Revolution was a revolution in the use of energy,” “... the use of coal combustion also started to cause emissions that we think were transported by winds up to the Himalayas.” The ice core samples were from the Dasuopu drilling site, 7,200 meters (23,600 feet) above sea-level.
Tracing the additional cause of the metal contamination at the world’s highest drilling site at 23,600 feet above sea level), the study identified the source and concluded: “What happens is at that time, in addition to the Industrial Revolution, the human population exploded and expanded,” Gabrielli further stated, “... so there was a greater need for agricultural fields — and, typically, the way they got new fields was to burn forests.” The presence of
of zinc, released when trees are burnt, was an indication that the forests were cleared for agriculture and housing purposes.
The study differentiates the discernible difference between “contamination” and “pollution”.“The levels of metals we found were higher than what would exist naturally, but were not high enough to be acutely toxic or poisonous,” Gabrielli said. “However, in the future, bio-accumulation may concentrate metals from meltwater at dangerous toxic levels in the tissues of organisms that live in ecosystems below the glacier.”
The University of Ohio team already found further evidence of human activities causing atmospheric pollution as revealed by the recent study in 2015. The air was polluted before industrial revolution in South America due to silver mining in Peru