**4.6 Socioeconomic and psychosocial risks**

In addition to the potential health benefits arising from the replacement of coal-fired power plants with plants using shale gas, the development of UOG can generate local and regional economic benefits that can improve the overall health of the population. Additional jobs and UPG producer taxes can stimulate the economy and lead to greater public investments in education and healthcare. The estimates vary but UOG related employment in the U.S. might be in the order of 1.7 million people with further growth projected [45]. However, negative health effects of UOG expansion can occur from "boomtown" effects, i.e., the extractive-resource driven rapid expansion of local economies, which is followed by equally fast declines when resource prices decline or other market forces throttle production. These effects have been well-documented in the 1970s and 1980s and they tend to hit the most vulnerable members of communities first and hardest [4]. Psychosocial studies have also documented the tensions that can rise in communities split into supporters and opponents of UOG, by concerns of the local residents about known and unknown side-effects of UOG production such as air and water contamination, and concern over social disruptions due to the sudden influx of mostly male workers from other parts of the country. Residents surveyed in rural parts of Pennsylvania, where Marcellus Shale development has grown rapidly, have mentioned feelings of loss concerning their old way of living, the degradation of pristine environments, and their sense of place. Psychosocial stress can manifest itself in a variety of symptoms that are difficult to diagnose. They can be exacerbated by a lack of trust in the UOG producers and local and state government regarding the safe development of these unconventional resources. The Geisinger Health System in Pennsylvania is undertaking a series of coordinated studies of the population it serves regarding self-reported symptoms [46].
