CIUDAD JUÁREZ.- State lawmakers from Chihuahua are siding with U.S. environmental groups against an Arizona mining company accused of polluting the air and soil on both sides of the border.

Chihuahua Deputy Salvador Gómez Ramírez said on Thursday that he and fellow legislators will travel to Austin, Texas, on Feb. 8, when the Texas Commission on Environmental Quality will hold a hearing on whether to renew an air quality permit for a copper smelting plant run by the Asarco mining company in El Paso.

The plant was temporarily shuttered in 1999 due to a drop in copper prices. It was last given an air quality permit in 1992, and the company has made efforts to begin operations again.

But community and environmental groups from both El Paso and Ciudad Juárez have opposed the reopening of the plant that sits on the banks of the Rio Grande, saying it is responsible for elevated levels of lead, arsenic and other pollutants in the area.

The company denies this, saying the area´s elevated levels of lead are due to the use of lead-based paint and other contaminants such as fertilizers.

Gómez Ramírez cited a recent study funded by the Sierra Club and carried out by Northern Arizona University Chemist Michael E. Ketterer, saying it revealed elevated levels of contaminants in a Ciudad Juárez neighborhood as well as in El Paso and other nearby communities.

Ketterer´s study compared lead isotopes from soil samples in El Paso and Ciudad Juárez with lead isotopes in the soil near the Santa Eulalia mine just outside the city of Chihuahua. Much of the copper ore refined in the El Paso plant comes from the Santa Eulalia mine, according to the report, which concluded the same contaminants were present in both sites and therefore Asarco was responsible.

Gómez Ramírez, of the National Action Party (PAN), said he has petitioned the federal government - including the Foreign Relations Secretariat, the Interior Secretariat and President Vicente Fox - against the possible reopening of the plant, but has yet to hear any response.

He said he would be present with a delegation of state lawmakers as well as legislators from Texas and New Mexico to protest against the reopening of the plant during the hearing next week.

AP reporter Alicia Caldwell contributed to this report.