The aim of this study was to evaluate the presence of potentially pathogenic mould and yeast-like fungi in the air in 5 seaside towns and cities between 2014 and 2017 and in 2018 when an emergency drop of crude sewage took place in the Gdańsk Gulf.
Materials and methods: Between 2014 and 2018 from Spring until Summer, 88 atmospheric air samples were collected within the area of 5 seaside towns and cities in the Gdańsk Gulf, including Hel, Puck, Gdynia, Sopot and Gdańsk-Brzeźno. The air was collected using the SAS Super ISO 100 sampler (Italy). The number of mould and yeast-like fungi was evaluated in the samples of atmospheric air using chloramphenicol-containing (YGC) and CHROM agar Candida media. The plates with media were incubated at 28 °C for 5 days. The number of colony forming units (CFU/m3) was calculated from the number of airborne fungi.
Results: In 2018 after an emergency discharge of sewage, a greater but statistically insignificant (p>0.05) number of mould and yeast-like fungi was found in the air in Hel, Puck, Sopot and Gdańsk-Brzeźno compared to 2014-2017 while no breakdown of the sewage treatment plant occurred. The Friedman test was used to investigate differences between the number of mould and yeast-like fungi, and a particular year of air sample collection in the studied seaside towns and cities. In 2018 potentially pathogenic and allergenic mould and yeast-like fungi were detected in the tested air, including Aspergillus fumigatus, Stachobytrys chartarum, Alternaria alternata and Candida sp. On the other hand, between 2014 and 2017 the above-mentioned species, which were detected in 2018, were not found. Moreover, by using the analysis of the contingency tables, with the indication of Pearson’s remainder values, it was demonstrated that the mean number of mould and yeast-like fungi in the respective years of the sample collection was close to the expected value in the seaside towns and cities such as Hel, Puck, Sopot and Gdańsk-Brzeźno. The result was statistically significant (p<2.22·10-16). The presence of statistically significant correlations between the number of mould and yeast-like fungi, and a relative humidity (p=0.009), wind velocity (p=0.002) and wind direction (p=0.007) have also been demonstrated.
Conclusions: It suggests that the detected species of mould fungi (Aspergillus fumigatus, Stachobytrys chartarum, Alternaria alternata) and yeast-like fungi (Candida sp.) after the failure of the sewage treatment plant can bring a health-related risk for people bathing in the seaside resorts. In the case of a raw sewage drop into the water it is advised that residents, especially children, the elderly and immunodeficient people, should be informed of the potential harmful effects to their health.
