Researchers of the Polytechnic University of Madrid (UPM) They questioned whether lettuce, in addition to being a source of health, is safe if grown in urban areas. And they also wondered about other qualities besides nutritional ones.
The Prospecting and Environment group (PROMEDIAM) of this university together with other researchers from the University of Copenhagen They have carried out various experiments to answer both questions.
They have carried out a joint study in which lettuces were exposed to different degrees of contamination atmospheric in different places in the city of Copenhagen.
According to the results obtained, the evaluation of the health risk derived from consumption of lettuce grown in an urban environment indicates safe levels (as long as clean soil is used during planting and the lettuce is properly washed before consumption).
MONITOR THE AIR
Furthermore, lettuces grown in the areas most affected by gas emissions and particulate matter, presented higher concentrations of pollutantsso these can serve as a complementary system to the network of fixed stations. Air quality control.
The work, they explain, "arises from the need to respond to two of the challenges that humanity currently faces: global food shortages and air pollution in cities" (the WHO estimates that 99 % of the population is exposed to pollution levels higher than recommended).
Lettuces were placed in various parts of the city with greater or lesser exposure to environmental pollution. The results showed that there was a relationship between the concentration of accumulated elements and the exposure environmentobserving an enrichment of anthropogenic contaminants in the samples located in the city center and near transportation routes.
ALWAYS WASH LETTUCE
The analysis also revealed that washing the samples achieved reduce the concentration up to 20 times of some contaminating elements deposited on the surface of the leaves and have not been transferred to the plant tissue.
"Consequently, a measure as simple as washing products grown in urban gardens before consumption can greatly limit the intake of toxic substances"say the researchers.
It was also verified that the concentrations of lettuce grown on a clean substrate did not exceed the legal limits established by the European Commission for this type of food.
An estimate of the daily intake of contaminants due to their consumption also did not exceed the maximum intake levels tolerable recommended by the main health agencies (EFSA and NAM).
Despite this, as highlighted Miguel Izquierdoone of the UPM researchers participating in the study, “to extend these results and guarantee the suitability of foods grown in urban areas that contribute to fight the global food crisis"The contribution of other agricultural products and in cities with worse air quality indices should be examined."