Expert assessment
2 min

CheniPRO: a study to assess occupational exposure to caterpillars with stinging hairs

What are the consequences of caterpillars with stinging hairs for the health of professionals working in woods, forests or green spaces? What occupations and regions are the most exposed? To answer these questions, ANSES and the Central Fund for the Agricultural Mutual Insurance Scheme (MSA) are jointly launching a nation-wide study called CheniPRO. 

What is the CheniPRO survey?

The CheniPRO survey is intended for employees and operators having their main occupation in the forestry-wood sector or in the maintenance and development of green spaces. It aims to:

  • Characterise the exposure of these workers to caterpillars with stinging hairs,
  • Determine whether these professionals have access to personal protective equipment,
  • Document the effects of exposure to these insects on occupational health.

The results will enable the most at-risk occupational categories to be identified so that recommendations may be put forward to reduce their exposure.

Who can participate?

In December 2022, ANSES will send 50,000 randomly selected professionals an email inviting them to complete an online questionnaire about their occupational activities, their exposure to caterpillars with stinging hairs, and their health status. Random drawing will ensure that the survey is representative of all workers, without the need to question them all.

This confidential and anonymous questionnaire will be available for one month following receipt of the email. The data collected will be analysed exclusively for the purposes of this survey, in accordance with the General Data Protection Regulation.

The conclusions of this work will be published in late 2023 and will be used as input for ANSES's ongoing expert appraisal on the health effects of caterpillars with stinging hairs.

What are caterpillars with stinging hairs?

Some species of caterpillars found in metropolitan France produce stinging hairs. This is the case of the pine and oak processionary caterpillars, the browntail moth caterpillar, and the Lithosia quadra (four-spotted footman) caterpillar in particular.

In stressful situations, these caterpillars release microscopic hairs that can become airborne. Humans can therefore come into contact directly with the caterpillar or the nest, or indirectly with hairs carried by wind or deposited on clothing, animal fur, tools, plants, infested wood, etc. These hairs cling readily to the skin and mucous membranes and can cause irritation and inflammation with or without allergic reactions.

Moreover, these caterpillar species can also have effects on certain plants such as oak and pine trees and on animals such as dogs, cats, and farm animals.