State-of-the-art. Several environmental factors and their relation to IDDM have been investigated in Sardinia:

1) the seasonal pattern. As already reported in other Countries, the peaks of incidence of the disease occur in the autumn-winter seasons and the prevalence of the disease in higher in males;

2) the impact of the temperature, precipitations and nitric content in the drinking-water. The Sassari province, which has the lowest incidence of IDDM in the Island, has also the lowest temperature, with the highest rainfall, but, unexpectedly, the highest nitric content in the drinking-water;

3) in the Island, there is no overlap between areas with high prevalence of IDDM and areas of both past and present endemic disorders, such as thalassaemia, malaria and G-6-P-D deficiency;

4) a positive correlation between the occurrence of IDDM in cow’s milk rather than breast fed children has not been confirmed, although a study was carried out in the province of Sassari in this respect (Meloni T et al, Diabetes Care, 20:340-342).

Future perspectives. The impact of environmental factors will be extended by comparing ‘hot’ and ‘cold’ areas for incidence of the disease. A possible relationship between IDDM and diseases affecting domestic animals (dogs, cats, cattle, equine and swine) will also be investigated.