Georgofili World

Newsletter of the Georgofili Academy

Is your football team playing badly? It may be air pollution. And what's happening to plants?

Football fans have thousands of reasons to justify the, at times, lackluster athletic performances of their idols. Apart, obviously, from “conspiracy theories” and referee plots, they range from the size and state of the pitch, the color of the t-shirts, the bouncing capacity of the ball, and other theories. A recent article published in The Guardian has introduced a new element: air pollution.  In fact, a group of German researchers has analyzed the correlations between air quality outside Bundesliga football pitches and player performance by counting successful passes and the conclusions are worrying. 
Toxic substances, even below the threshold allowed by environmental regulations, are responsible for significant reductions in the parameters chosen.
It is by no means the first time that air pollution has been associated with a decrease in human physical (as well as cognitive) performance. For example, it has been assumed that if the daily average of ozone goes down by 10 ppb, farmer productivity increases by 5.5% (http://www.nber.org/papers/w17004). Remaining in the sport milieu, worries during the Beijing Olympic Games  (2008) (http://www.ncbi.nlm.nih.gov/pubmed/18512178), as well as during the London games (2012) (http://www.decodedscience.org/london-2012-olympics-could-air-quality-affect-athlete-performance/16274) were well-known, especially for the long-term competitive activities.
However, what are the effects on plants that grow with significant concentrations of harmful substances in the air?
Phyto-toxicology is now a mature discipline with hundreds of experts and research groups that, often with integrated approaches, analyze the physiological and metabolic aspects of plants under stress ranging from the subcellular to the population level. A number of experimental studies and modeling exercises has for some time highlighted ozone’s harmful consequences on the soil commonly found even in rural and forest areas and not only in urban centers (http://www.annualreviews.org/doi/pdf/10.1146/annurev-arplant-042110-103829). The effects (type and intensity) depend on parameters linked to exposure (chemical species, concentrations, and mixtures), the plant’s response capacity, and environmental factors (in these terms, the famous “disease triangle”, the working basis for plant pathology, is inventively stated but, in reality, pollutants are basically pathogens). Qualitative and quantitative reduction of plant productivity, a decrease in forest biomass, and changes in the composition of spontaneous and semi-natural communities are the main entries that characterize the impact of the most common situations of pollution that also imply the impaired provision of ecosystem services. These trends are generally growing, notwithstanding the legislative measures adopted in many places. In Europe and North America, the situation has somehow been “stabilized”. Nevertheless, a rapid increase of contaminations is being witnessed in those countries undergoing turbulent economic and social development, beginning with China, in which we find as many as 16 of the 20 most polluted cities in the world.
It is easy to identify economic aspects linked to reduced productivity, even if it is not banal to understand who the real victims are (producers, processors, dealers, consumers) considering the rules in the formation of market prices. However, it is less simple to quantify the consequences in ecological terms, for example, as regards forest depletion that has been distressing vast areas in Europe for years. All this then must be read by also taking into consideration the on-going (or at least predicted) climate change, starting with global warming. Actually, considering the complex verified interactions, what happens is that the ozone (an important greenhouse gas itself) directly reduces the capacity of vegetation to fix carbon (decreased photosynthesis), which contributes to a greater presence of this climate-altering gas (with a rise in temperature) followed in its turn by an increase of natural smog precursors (biogenetic hydrocarbons produced by the stressed plants), some of which are agents of climate forcing, and so on in an endless series of actions/reactions. 
All this in an increasingly less stable and more hostile environment where, for example, heat waves (and peaks of photochemical oxidants) we suffered in specific years (e.g.;. 2003, 2012, 2015) will become increasingly more frequent with severe consequences also in terms of mortality and human morbidity (https://royalsociety.org/~/media/Royal_Society_Content/policy/publications/2008/7925.pdf).
It is not surprising, thus, that air pollution represents a serious menace to food security (food availability) worldwide, at least in the northern hemisphere. A significant reduction of tropospheric ozone concentrations would represent an excellent opportunity to increase the output of strategic crops (such as wheat, soya, rice, maize) without making environmental and economic costs worse by increasing cultivated surfaces and the use of chemicals as pesticides and fertilizers (http://www.sciencedirect.com/science/article/pii/S1352231011000070).
In addition, our scientific community has been active on these themes for some time. In November 2006 the first national event was held in Pisa where numerous working groups discussed topics linked to the levels and effects of tropospheric ozone on agrarian and forest ecosystems.
The initiative gained general consensus and was the starting point for successive, even international projects. Among those to be pointed out is TreeCity, a recently completed PRIN project. On the occasion of the meeting’s 10th anniversary, the Department of Agrarian, Food and Agri-Environmental Sciences at the Pisa University, TerraData environmetrics (a Siena University spin-off) and the Edmund Mach Foundation – Research Center and Innovation (San Michele all’Adige), have organized a study day to evaluate updates that have emerged in the last 10 years from Italian research on these topics. The meeting is dedicated to the memory of Professor Giovanni Scaramuzzi 15 years after his death. To him is owed the pioneering insight of turning human and material resources towards these studies. 

The program for this event (24 November 2016), sponsored by the Georgofili Academy and  with free attendance, can be seen at the link  http://www.agr.unipi.it/images/eventiconvegni/2016/24nov16.pdf