Oil and gas production threatens US air quality

Extremely high air pollution is being reported in the US from unconventional oil and gas production, during which extraction companies use aggressive means to tap reserves that do not readily flow to the surface.

The information was logged by local people recruited and trained by researchers to take air samples at sites in Arkansas, Colorado, Ohio, Pennsylvania and Wyoming.

The figures were recorded during heavy industrial activity or when residents suffered symptoms such as headaches, nausea and dizziness.

US companies are extracting unconventional oil and gas supplies after a decline in the conventional stock, much of which is obtained through more conservative fracking procedures.

However, analyses by a team from the University at Albany, New York state, showed the drilling and hydraulic fracturing used in releasing less accessible oil and gas underground reserves produced far higher pollution.

The study, the first based on lay sampling, found benzene content ranging from 35 to 770,000 times higher than background levels. The analysts calculated concentrations were 33 times the amount created from pumping fuel into a car. The exposure for five minutes at a Wyoming site was considered equivalent to that from living in Los Angeles for two years or Beijing for eight and a half months.

Hydrogen sulfide content was measured by the Occupational Safety and Health Administration as 90 to 60,000 times higher than background levels, enough to cause eye and lung irritation after an hour’s exposure. Other effects were fatigue, appetite loss, headache, irritability, poor memory and dizziness.

Formaldehyde content was 30 to 240 times higher than background levels.

Cancer can be caused by benzene and formaldehyde but may take years to develop.

The pollution reports on the extraction companies could influence government policy, suggested lead researcher David Carpenter. He said: “Our findings can be used to inform and calibrate state monitoring and research programmes.”