While there has been considerable reporting on the effects of SO2 on humans, animals are even more at risk.
RÚV reports that farmers in the Icelandic countryside are worried about what effects the gas will have on their sheep, many of whom have not yet been herded. While a great many animals in the east and the north – where the pollution has been greatest – have been rounded up, their still remain a great many behind, grazing in the mountains.
Some farmers have reported that even the rounding-up itself is made more difficult by the pollution, as horses get more tired much faster from having to breathe SO2 for extended periods.
Auður Arnþórsdóttir, a veterinary specialist at the Icelandic Food and Veterinary Authority (MAST), told reporters that SO2 has the same effects on humans as it does on animals – in particular, damage to eyes and the respiratory system. In fact, the MAST also reports that animals might be at even greater risk than people, as they spend considerably more time out of doors.
As such, MAST is advising area farmers to not subject their animals to too much stress or exertion, and to assume that tolerable SO2 levels for humans and animals are the same: 350µg/m3 an hour or 125µg/m3 per 24 hours.