Pollen and health
Useful information for local councils
Pollen grains and fungal spores are reproductive cells, that is, they are involved in forming new individuals. So these cells are absolutely necessary for maintaining plant life on this planet; without them, there would be no fruits and no wild mushrooms and, in the long run, the species creating them would also die out.
When pollen and spores perform their reproductive function, their content is expelled outwards into the atmosphere. If this takes place in places suitable for reproduction, the plant's life cycle follows a proper course. However, when they come into contact with human mucous membranes (in fact, with the mucous membranes of all animals), the cell content may trigger allergic reactions in sensitized individuals.
These allergic reactions may manifest as rhinitis (mucus secretion in the nose), conjunctivitis (watery eyes) or asthma (breathing difficulties). Aerobiology (the study of the diversity and quantity of pollen and spores in the air) may help detect what is causing the allergy and improve the quality of life of affected people.
The most allergenic pollens in Catalonia are produced by the lichwort, grasses, cypress, olive tree, London plane, goosefoots (Chenopodium) and plantain. More locally, hazel, birch, mugwort and others are significant. There may be other species that are still little known from the respiratory allergy viewpoint, such as evergreen oaks, deciduous oaks, cork oaks and kermes oaks. It is important to know what the plant causing the problem looks like. Images of the most important plants can be found in the section "Allergenic plants". As regards spores, the most problematic are Alternaria and Cladosporium.
The Point of information on Aerobiology provides municipal gardening professionals with up-to-date information about different plants' advantages and disadvantages in public urban spaces and can therefore contribute to improving citizens' quality of life.
- Recommendations when choosing species to be used as street trees.
- List of plants whose pollen has a proven allergenic activity.
- List of plants whose pollen has a possible allergenic activity.
- Guide to urban green. Trees and gardening. Services of Equipment and Public Space. Diputació de Barcelona.
- Application Planttes is a public science project that aims to report on the presence of allergenic plants in the environment and the level of risk of allergy depending on their condition.
- Sociedad Española de Alergología y Inmunología clínica.
