Joan Gual, the ports authority president (centre), with university representatives. | Pere Bota

The Balearic Ports Authority last year commissioned the University of the Balearic Islands to undertake a survey of air and noise pollution in Palma. The results of the first phase of this survey suggest that ferries, cargo ships and road traffic along the Paseo Marítimo generate higher levels of contamination than cruise ships.

The results cover the period from September last year to June this year. They are based on data captured by a series of sensors that were positioned in the port. Jordi Llabrés, the vice-rector of innovation at the university and one of the researchers, explained at a presentation of the results that the sensors analysed the correlation between activity in the port and its contribution to environmental contamination - the levels of noise, of particulates and gases.

The survey, named SmartSensPort, used eight monitoring stations. In terms both of daily noise and particulate emissions, cruise ships were well below ferries, while "others" were substantially higher than ferries.

The researchers say that it will be necessary to study further factors in order to explain contamination, but the general conclusion from the first phase is that road traffic is the worst offender. Cruise ships, the university notes, use more modern technologies that cause less contamination than ferries.