The town at the center of a Guardian series, where the cancer risk is 50 times the national average, is critical of a planned monitoring system

Environmental Protection Agency officials on Tuesday pleaded with community members in Reserve, Louisiana, to back a new air monitoring system being installed by the agency, which they claim will better measure pollutants from a nearby chemical plant emitting the likely human carcinogen chloroprene.

Reserve, the subject of a year-long Guardian series, Cancer Town, is home to the highest risk of cancer due to airborne toxins, according to EPA data, which found that a census tract next door to the plant has a cancer risk 50 times the national average.

The EPA has been monitoring chloroprene emissions at six sites near the plant, which is run by the Japanese chemicals firm Denka, since 2016 but recently announced plans to alter how it records emissions. The agency currently takes a routine air reading once every six days, with chloroprene emissions regularly dozens of times above the lifetime exposure threshold recommended by the agency of 0.2 micrograms per cubic meter.

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The new system, involving new monitors named Spods, will be designed to catch “spikes” in chloroprene whenever they occur, meaning officials expect more readings to occur throughout the programme’s six-month length.

“Our goal on this is to find chloroprene,” said David Gray, deputy regional director of the EPA’s region six office at a community meeting in Reserve on Tuesday evening.

The official told residents that the agency had not yet decided at what level a “spike” would be determined but that it was likely to be well above the agency’s own lifetime exposure guidance of 0.2 micrograms. The monitors will also not directly measure for chloroprene itself, but other volatile compounds that researchers believe indicate heightened chloroprene presence in the ambient air.

Speaking to the Guardian after the meeting, Gray said the ultimate timeframe of the program had not been assigned, but officials were determined to capture a so-called “turnaround” at the plant, when day-to-day operations are ceased for renewal and it is expected elevated levels of chloroprene are released into the air.

He suggested that data showing chloroprene spikes would allow the EPA to engage with plant operators and work on ways to reduce emissions.

“Clearly for us it’s fastest if people act voluntarily, if we show them things that are reasonable, easy to do, give great benefit and don’t cost a lot,” Gray said. “But we do have the harder toolbox, which is legal and enforcement.”

The new monitoring system was met with some criticism by local community members who have urged the EPA to take a harder enforcement line on Denka and also to measure for other pollutants in the air in Reserve.

“We need to do it, and do it quickly because too many generations have been damaged by this,” said Margaret Fiedler, a local resident. “It affects the ability of the children to learn. I’m at the end of my road, but I don’t want to see the children in Fifth Ward [an elementary school next to the plant] have learning disabilities.”

Gray was also questioned by lawyers representing residents in a class-action lawsuit against Denka, over a short series of emails the official had with the plant’s manager, which lawyers suggested indicated a close relationship between the EPA and Denka.

Gray rejected the suggestion. “It is not my intention to come here and undercut you in any way,” he told the meeting. “I am committed to this project … It breaks my heart to make you think anything else.”

A spokesman for Denka said on Wednesday that the company had no position on the new air monitoring system, but suggested the old system had given the public “considerable information”.

The company have frequently highlighted the $35m spent to install emissions controls in recent years. Denka said these installations have reduced chloroprene emissions by 86%. It has been challenged on this claim by the Louisiana department of environmental quality (LDEQ).