MISSOULA — Questioning of a federal official prominent in the government’s response to asbestos contamination in Libby continued Tuesday at a trial on allegations that W.R. Grace & Co., and five of its former officials, knowingly tried to conceal asbestos hazards in the northwestern Montana town. Defense lawyers questioned Paul Peronard, who became the U.S. Environmental Protection Agency’s on-scene coordinator nearly 10 years ago in Libby. Grace used to operate a Libby vermiculite mine laced with asbestos that became dispersed in the community. Peronard testified earlier that misinformation from a Grace spokesman derailed EPA efforts to gauge the scope of asbestos contamination in Libby and to develop a cleanup plan targeting the town’s most contaminated areas, the Missoulian reported. He said Grace evaded EPA requests for information by not supplying corporate documents that explained how the company provided asbestos-tainted mine waste for use on school running tracks in Libby. Defense lawyers said that based on EPA instructions, Grace was not required to provide those documents. Grace, a global chemical and construction materials company, and the five former officials are accused of conspiring to violate federal air-quality requirements and obstruct justice.