NEW YORK, March 15 (Xinhua) -- Many residents of East Palestine in the U.S. state of Ohio are suspicious of the environmental contractor Norfolk Southern has brought in to measure chemical exposures following last month's massive train derailment, toxic spill, and chemical burn off, reported the Time magazine on Tuesday.

"The residents of East Palestine have reason to be suspicious," said the author David Michaels, a professor at the Milken Institute School of Public Health at George Washington University, while introducing the environmental contractor, the Center for Toxicology and Environmental Health (CTEH).

"My experience working at government regulatory agencies in both the Clinton and Obama Administrations has led me to conclude that CTEH's business model often entails providing clients with the ammunition to slow regulation or defeat court claims," said the professor.

"I believe consulting firms like CTEH are tangled in irreparable conflicts of interest; if they produce results showing the clients' products are harmful, it seems likely that their client base would quickly disappear," he noted.

Over the last decade, CTEH has become the go-to contractor for corporations looking to follow up on environmental disasters to which they've been connected. It has done environmental testing after other derailments where toxic chemicals were released, like the 2012 derailment in Kentucky of a train carrying butadiene (a human carcinogen), and other Norfolk Southern derailments in South Carolina and Georgia.