24 h patterns with high frequency components in the incidence of pediatric trauma were validated and quantified in one of our earlier studies. Herein, we further explored the temporal-high frequency, 24h, weekly (7d), hemi-weekly (3.5d), and annual - patterns in traumatic (1990-1997; n = 15,110 events) and non-traumatic pediatric surgical emergencies (PSE) (1992-2001; n = 5,593 events) as well as automobile accidents (AA) (1990-1997; n = 67,712) in the County of Vaud, Switzerland. The latter served as a reference system of human adult activity and risk. Two-way ANOVA, chi(2), correlation, and cosinor analyses were used as statistical tools. A 24h pattern, reproducible from year to year, was validated in traumatic and non-traumatic PSE and AA. The 24h patterns were not correlated and differed front one another in terms of their acrophase (peak time) and amplitude. A gender-related difference was found only in the non-traumatic time series for weekly (7 d) and hemi-weekly (3.5 d) patterns. The latter were detected in boys but not girls. No statistically significant difference was found in the acrophase and amplitude between boys and girls in the temporal patterns of other periods. An annual pattern was validated in automobile accidents (acrophase: 4th of September +/- 37d (SD)) and pediatric trauma (acrophase: 14th of June +/- 10 d), but not in non-traumatic PSE. These results suggest that environmental modulations differ between the incidence of traumatic and non-traumatic PSE. Presumably, the two phenomena involve different aspects of the temporal organization and/or different levels of susceptibility of a set of biological rhythms to environmental factors.
