Health problems in the Netherlands related to recreation in surface water, 1990-1999
| Nature of complaint | 1990 | 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 |
| number of incidents | ||||||||||
| Intestinal complaints | 14 | 5 | 7 | 4 | 18 | 34 | 4 | 30 | 10 | 15 |
| Skin infection | 5 | 14 | 13 | 2 | 11 | 27 | 15 | 32 | 22 | 22 |
| Weil's disease (leptospirosis) | 3 | - | 1 | 2 | 1 | 5 | - | 2 | 7 | 7 |
| Ocular disorders | - | - | - | - | 26 | 18 | - | 8 | - | - |
| Other/unknown | 7 | 7 | 1 | 1 | 3 | 1 | 2 | 10 | 7 | 7 |
| Total | 29 | 26 | 22 | 9 | 59 | 85 | 21 | 82 | 46 | 54 |
| Source: RIVM | RIVM/EDC/Oct02 | |||||||||
Developments in numbers of complaints
The number of complaints related to recreational bathing appears to be linked mainly to the temperature of recreational water in the summer. The summers of 1994 and 1995 were hot and many complaints were recorded. The numbers of people per incident were also high. 1997 was another hot summer with many incidents, but with significantly fewer patients than in 1994 and 1995. In the other years, there were usually fewer than 25 patients per incident (maximum 25).
