Both Zero and Quercus stressed the need to guard against the dangers of noise caused not only by planes but also by the entire operation of an airport.

The president of Quercus, Paulo do Carmo, considered the Environmental Impact Study (EIA), whose evaluation is open to public consultation until 19 September, as "weak" for accessibility.

"We cannot have only road and river transport to the airport and trucks cannot and should not be used to supply it with aviation fuel," he said.

Zero also raised concerns about birdlife in the area, since habitats will be affected by the construction of an airport and because of the risk of accidents due to bird collisions with aircraft, and the impact of ultrafine particles generated by aircraft on public health.

The president of Quercus said that if practices are adopted to mitigate the effects of these concerns, particularly concerning noise that could affect the quality of life of people living in Montijo and surrounding municipalities, there are conditions to approve the EIA.

Zero also appealed to the government to discuss the two infrastructures, Portela (Lisbon’s current airport) and Montijo, "as a whole", so that "in the next 40 years no decision is taken that affects the health of many thousands of people," with the permanence of Lisbon airport within the city.

"For us, it is crucial to discuss the future of Lisbon airport. Not carrying out a strategic environmental assessment in this area is a huge mistake", added Francisco Ferreira.