By Diana Washington Valdez – El Paso Times
Juarez residents watch the Asarco smokestacks fall early Saturday morning. (Jesus Alcazar / El Paso Times)
Last week’s demolitions of Asarco’s smokestacks did not produce harmful amounts of microscopic dust particles in the region, according to preliminary monitoring data collected from multiple stations.
“The data collected from the monitors show that the demolition work was a well-controlled event, and that the dust measures that we used were effective,” said Robert Puga, the trustee in charge of cleaning up the former smelter site in West El Paso. “The data shows that dust levels exceeded national standards (for PM-10 particles) at only one site.”
The monitoring stations took readings for PM-2.5 fine dust particles and for PM-10, which are somewhat coarser dust particles. The National Ambient Air Quality Standard for PM-2.5 for a 24-hour or daily average is 35 micrograms per cubic meter of air and for PM-10 the standard is 150 micrograms per cubic meter of air.
The monitor at the site labeled “west,” which recorded 152 micrograms for PM-10, is actually southeast of the felled stacks and north of Paisano Drive. The highest readings for PM-2.5 occurred at three sites labeled “west” (76 micrograms), “southwest” (65 micrograms) and “east” (53 micrograms).
A monitor at Calavera, the neighborhood nearest the demolition, measured 6 micrograms for PM-10 and 4 micrograms for PM-2.5.
The wind was blowing in a southeasterly direction at about 4 mph during the demolitions.
Experts say exposure to fine dust particles might contribute to impaired lung function, bronchitis and heart disease. At-risk groups include children, the elderly and people with respiratory problems.
In addition to the Puga’s 16 monitors, the trustee also received data from three of the Texas Commission on Environmental Quality’s (TCEQ) monitor stations, and from three of the Mexican government’s monitors.
Lab results from five high-volume air samples — three from Mexico and two from the U.S. — are pending and should be available soon, Puga said.
The 47-year-old, 828-foot Asarco smokestack falls to the ground April 13. (Rudy Gutierrez / El Paso Times)
TCEQ, which is helping to oversee the trustee’s environmental remediation, issued the following statement after reviewing preliminary data:
“Preliminary data has not been validated and (is) therefore subject to change,” the TCEQ said. “Concentrations remained in the “good” range for carbon monoxide, nitrogen oxides, ozone, and sulfur dioxide all weekend (April 12-14). There was a short lived spike of elevated levels of PM-10 and PM-2.5 on Saturday morning. There were elevated levels of PM-10 and PM-2.5 Sunday morning and lasting until early Sunday afternoon. These particulate matter concentrations remained below a level of health concern all weekend.”
Mariana Chew, president of Citalli Engineering and a faculty member for the North American Development Bank’s utility management institute, said she and five other environmental and civil engineers from both sides of the border questioned the accuracy of the monitoring data.
“More research is needed to verify the impacts of the demolitions,” Chew said. “The cloud event generated by the demolitions lasted from 6 to 8 hours, and that means the readings should have been multiplied by three to get a better 24-hour average reading for that single event. Because of this, we can’t use the data as a baseline for future research, which also means that those who plan to investigate the impacts later will need to develop other methods to make up for this.”
Chew said the low readings for the Juárez side of the border, 21 to 24 micrograms for PM-10 and 11 to 12 micrograms for PM-2.5, should be challenged based on what residents in Anapra/Juárez physically experienced.
“I stood on the Juárez side when the demolitions took place, and we got hit by the huge cloud of dust that headed straight to us,” she said.
“Besides, fine dust particles are proven to be harmful in any amounts because they have the ability to penetrate lung tissue and other parts of the respiratory system.”
According to the trustee’s website, the start time for the 24-hour monitoring began at noon April 12. Chew says it should have begun with the demolition.
Puga said the TCEQ off-site monitors and the Juárez off-site monitors support the readings on the trustee’s network of 16 monitors.
“We operated 26 large misting cannons around the fall zones 30 minutes before and after the demolitions to saturate the air with water and wet the fall zone,” Puga. “My main priorities were safety to people and property, for the stacks to fall the right way and to control the dust. All of these things were achieved.”
Diana Washington Valdez may be reached at dvaldez@elpasotimes.com; 546-6140.
Source: http://www.elpasotimes.com/news/ci_23076956/tests-asarco-dust-not-harmful