VATICAN CITY (AP) — Pope Francis will mark the fifth anniversary of his ecological manifesto by visiting a southern Italian region where decades of toxic-waste dumping by the mob have polluted the environment and sickened its people.

The diocese of Acerra announced Francis’ May 24 visit on Saturday. It said his trip to the so-called “Land of Fires” would be a source of joy and hope for the region’s families, and especially their cancer-stricken children.

Italy’s National Institutes of Health said in a 2016 report to parliament that residents of the area near Naples suffered higher-than-normal incidents of death and cancer due to exposure to contaminants from illegal dumps and the burning of urban and hazardous waste.

Residents have long complained about adverse health effects stemming from the dumping, which has poisoned the underground wells that irrigate the farmland that provides vegetables for much of central and southern Italy. The fires and dumping are blamed on the local Camorra mob, which controls the area.

The bishop of Acerra, Antonio Di Donna, said he hoped Francis’ visit would bring a “strong appeal to public institutions so that the truth finally comes out about our land.”

In his 2015 environmental encyclical, “Praised Be,” Francis called for a cultural revolution to correct what he said was a “structurally perverse” economic system in which the rich exploited the poor, turning Earth into an “immense pile of filth.”

Francis has also repeatedly condemned Italian mafiosi, saying they are excommunicated and demanding they change their ways.