MIDDLESEX TWP — An expert from the Southwest Pennsylvania Environmental Health Project said invisible, toxic emissions spew into the air during all phases of the unconventional gas drilling process, but a method exists to minimize that exposure.

Tyler Rubright gave a presentation Thursday night at the Middlesex Township building before about 20 residents.

Marcellus Outreach Middlesex (MOM) hosted the forum, which began with side-by-side photographs of a natural gas storage tank. In one photograph, the tank looks harmless under a bright blue sky. But the other photograph, which was taken with an infrared camera, shows vapor and emissions spewing from the tank.

“Often times the gases are invisible, so people feel they’re OK once the major drilling has subsided,” said Diane Arnold, a co-founder of MOM, “but the emissions are still there.”

Rubright listed the dangerous pollutants and contaminants that he said are contained in the emissions and their potentially dire effects on the body.

He said the tiny airborne pollutants, which are 1/20 the width of a human hair and smaller than a particle of dust, find their way inside the lungs of those living near gas wells or gas plants.

“Down the line, they can cause cancerous issues and adult asthma,” Rubright said of the pollutants’ effects on the lungs.

But he explained anyone can use the air exposure model developed by his group to avoid maximum exposure. It involves knowing when there would be good and bad days for air pollution.

Basically, Rubright said sunny, breezy days are the least dangerous when it comes to inhaling invisible pollutants.

Cloudy, still days are dangerous for young children, the elderly, and those with breathing problems like asthma because the pollutants stay close to the ground.

Cloudy days that are windy are somewhat better, but bright, warm sunny days provide the best air quality for those living near an unconventional gas drilling facility.

He said a still night provides the worst air quality because the pollutants stay near the ground when warm air is absent.

He said Pennsylvania’s topography also can be a problem since pollutants tend to lie in valleys.

“You should also know which direction the (gas) facility is from your residence and how far away it is,” Rubright said.

He said since the weather in Western Pennsylvania tends to blow from west to east or south to north, those who live east of a gas extraction facility will inhale the most pollutants.

Rubright said more information on the model are available at www.environmentalhealthproject.org.

Patrice Tomcik talked about the potential effects of gas extraction activities on children. The information was from pediatricians, toxicologists and other experts, Tomcik said.

She is a member of the group of parents who are trying to have a two-mile overlay zone placed around the schools in the Mars School District before six wells are drilled at the Bob and Kim Geyer farm on Denny Road. Heavy industrial uses, including unconventional gas drilling, would be prohibited in the zone.

Tomcik said diesel exhaust from the thousands of trucks that access well sites, drilling chemicals, fracking fluid, flowback fluid from underground, the release of gas from well heads, flaring, and waste ponds can have harmful and long-term effects on children.

She said toxins build up in growing bodies because they cannot be flushed out as quickly as they are in adult systems.

She said the parent group also worries that silica dust clouds, which result when sand, water and chemicals are mixed for the drilling process, will migrate to the school properties.

“Silica dust is the number one issue for workers, as far as (the state Occupational Safety and Health Administration) is concerned,” Tomcik said. “It is a carcinogen.”

Diane Sipe of Marcellus Outreach Butler said the health of citizens should be the first concern in gas extraction.

‘We need to turn our thinking,” Sipe said. “We need to start demanding that our health and welfare are considered first, not profits.”