Lake Garda Algal Bloom Not Expected to Pose Human Health Risks, Preliminary Findings
This conclusion emerges from some preliminary results of analyses on samples examined at the Centro dell’Asl di Brescia and at the Istituto Superiore di Sanità di Roma. These samples have already been sent to the Hygiene Office of the local District of the ASL, based in Salò, which is responsible for surface water analysis in the area. Only after the completion of ongoing tests at the two health laboratories will it be possible to better understand the extent and potential consequences of the surface algae observed in recent days.
Interventions and ongoing analyses
The bloom was noticed incidentally by a lake water bathing analysis technician on September 30th. The technician collected several samples and, after reporting to supervisors, transported them to the Laboratorio di Sanità Pubblica, the former multizonale health facility based in Brescia.
At the same time, thanks to an agreement previously signed between the Asl bresciana and the Ministry of Health, some samples were also sent to the Istituto Superiore di Sanità, which deals with issues related to bathing water safety. “This isn’t the first time algal blooms have appeared on Lake Garda,” immediately clarifies Dr. Viola from the Distretto di Salò. “So far, they have never caused problems or prompted safety measures.”
Have the mayors been asked to issue restrictive ordinances? “Not at all, because, as I repeat, the initial results communicated informally are not worrisome enough to justify public health protective measures,” he affirms.
Monitoring and regulations
Meanwhile, water samples have been taken from areas near the intake points of the lakeside municipalities’ aqueducts, to provide greater safety assurances for residents. However, there are no specific regulations concerning algae, unlike those for bathing water analysis.
For bathing waters, clear standards exist, based on chemical and biological parameters. “It’s a relatively new field,” confirms Viola. “Research on algae is still evolving, but currently, there are no standardized parameters set for them.”
A couple of weeks ago, due to a “lagheggiata” (a large accumulation of algae), tons of macrophyte plants surfaced and ended up on the shores. Fortunately, the swimming season had already terminated by then.
