Honey bees as an aid in improving labour conditions in sweet bell pepper greenhouses: Reduction of pollen allergy

Sweet bell pepper is the most important greenhouse vegetable crop in the Netherlands. It is grown on an area of 10,000 hectares, and about 8000 people are working in these greenhouses. One third of these workers sooner or later develop an occupational allergy to the sweet bell pepper pollen. The symptoms range from itching, blocking of the nose as well as a sniffling nose, to asthma. The pollen falls down from the flowers when the plants are shaken, which occurs when people are cutting fruits or when they prune or twine the plants. In a pilot study, a number of greenhouses in which honey-bee colonies were introduced were compared with greenhouses without honey-bees. In the greenhouses with honey-bees, hardly any pollen was present on the anthers of the flowers, since it was collected by the honeybees as a food for their larvae. In flowers of plants in greenhouses without honeybees, pollen was present most of the time. The symptoms of allergic workers in the greenhouses were significantly reduced by the presence of honey-bees, as was deduced from questionnaires in which the workers were asked to mark the intensity of the symptoms during the past two weeks on a Visual Analogue Scale. The possible beneficial impact of the application of honey-bees on a larger scale needs further research, as well as answering the question of a possible prevention of this occupational allergy in sweet bell pepper horticulturists by honey-bees. The required or optimal number of bee colonies per area greenhouse needs also to be studied.