The impact of different air pollutants on vegetation and crops has been studied for over 35 years in the framework of the UNECE Convention on Long-range Transboundary Air Pollution, through its International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation), led by the UK Centre for Ecology & Hydrology. The monitoring and research undertaken has continuously enhanced the understanding of impacts of air pollution and their relevance for food production and food security. 

At the recent annual meeting held in Kaunas, Lithuania, over 60 experts gathered to review new evidence of the impacts of certain air pollutants on vegetation and crops.  

Impact of ozone on food production  

Some crops, including the staple food crops wheat, rice and bean, have been found to be particularly sensitive to certain types of air pollution. Ground-level ozone — formed when emissions from vehicles and industry (e.g., nitrogen oxides) react with other pollutants in sunlight — affects plant growth and is estimated to cause global crop losses for staple foods.  

The situation in the Mediterranean region is particularly critical due to high ozone concentrations, which is why studies on ozone sensitivity of different genotypes of the same crop can give valuable information on alternatives in ozone-polluted Mediterranean climatic areas to maintain sustainable food production. 

Mosses as monitors of microplastics pollution 

While plastics have only been produced for around 70 years, the growth in plastic waste has been exponential. If not managed in a sound manner, plastic ends up in the environment, polluting soils, water bodies, and oceans, with dire consequences for biodiversity and human health. New evidence now shows that when broken up further, microplastics can also be transported by air. Research finds that atmospheric microplastics can be detected in mosses. 

Naturally growing mosses are used as biomonitors of atmospheric deposition of pollutants, such as heavy metals and nitrogen, to assess spatial pollution concentration patterns and temporal trends across Europe and beyond. Since 1990, mosses have been sampled every five years in the framework of ICP Vegetation and have provided a good indication of areas at risk from high pollutant deposition.  

The latest research, discussed at this year’s meeting, shows that mosses can also be used to assess deposition of atmospheric microplastics. For example, findings from France, Italy, Lithuania and the UK all show that a variety of polymers can be detected in mosses, demonstrating their suitability for monitoring of airborne microplastic deposition.  

With the international negotiations to develop an international legally binding instrument on plastic pollution scheduled to be completed by the end of the year, plastic pollution has been high on countries’ political agenda. The results from the moss research on microplastics underpins yet again the importance and urgency of reducing plastic pollution through a global instrument.