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A new preliminary report from the Southwest Pennsylvania Environmental Health Project has revealed that at least 27 people in one Pennsylvania county developed health conditions related to fracking over a period of 18 months. These numbers include only the people whose conditions could convincingly be linked to fracking operations.

The study is the first long-term research into the effects of hydraulic fracturing on public health and, while it clearly shows that the industry has been too optimistic to claim that no one could be harmed by drilling operations, the damage might actually not be as serious as critics have warned, the Huffington Post reported.

Among the 27 cases of people believed to have been affected by fracking, there were 13 cases of respiratory problems and seven cases of skin rash. Four people had eye irritation and three more suffered from dizziness and headaches, the report found. Researchers explained that the skin problems were the result of contact with water, while all other cases were linked to lower air quality.

RELATED: Study finds increased arsenic levels in groundwater near fracking sites

With these figures in mind, the Southwest Pennsylvania Environmental Health Project has suggested that the impact of fracking on air seemed to be more prominent than the impact on water, contrary to what many campaigners claim. Another interesting finding that the report presented was the fact that the large processing stations that send gas into pipelines across the country may be more harmful than drilling sites.

This is just a preliminary report and the findings should not be seen as conclusive evidence, the Huffington Post noted.