Oak processionary posed a health threat. In April 2018, an outbreak of the caterpillars was reported across Greater London and surrounding areas. The moth is now fairly common in Belgium, notably in the Campine but also elsewhere, with fluctuating population numbers from year to year. In 2007 infestations in the Belgian province of Limburg were so acute that soldiers were deployed to burn them. In the Netherlands, the caterpillars are dealt with by biological pest control. Local authorities use, like in Germany, fluids containing bacteria that are toxic only to the caterpillars. These fluids are sprayed onto the infected trees. Furthermore, an
California Office of Environmental Health Hazard Assessment California Office of Environmental Health Hazard Assessment The Office of Environmental Health Hazard Assessment, commonly referred to as OEHHA (pronounced oh-EEE-ha), is a specialized department within the cabinet-level California Environmental Protection Agency (CalEPA) with responsibility for evaluating health risks from environmental chemical contaminants. OEHHA is the scientific adviser within CalEPA and provides the health effects assessments that assist regulatory decision makers within CalEPA, the California Department of Public Health, and other agencies and non-governmental organizations (see below). This includes assessing health and environmental risks from: In May 2009, Governor Arnold Schwarzenegger proposed to "eliminate and transfer the functions" of OEHHA