[Quantitative study by grey system on the latent period of lung cancer induced by air pollutants].

OBJECTIVE

To calculate the latent period of lung cancer induced by air pollution.

METHODS

The degree of grey incidence (DGI) between the concentrations of TSP or SO(2) and the mortality of lung cancer were assessed through a grey system model. According to the maximum values of DGI, the total latent period of lung cancer was calculated. Data was collected in H city.

RESULTS

The maximum DGI value of TSP was 0.886 while the relationship between the comparison sequence from 1985 to 1989 and the reference sequence from 1994 to 1998 was greatly correlated. The maximum DGI value of SO(2) was 0.919 while the relationship between the comparison sequence from 1986 to 1990 and the reference sequence from 1994 to 1998 was most correlated.

CONCLUSIONS

The latent periods of lung cancer induced by TSP and SO(2) were 7 and 8 years respectively in H city. The model of grey system was less affected by the confounding factors, and the calculation process was relatively simple. A feasible and useful new way was provided by the model of grey system for quantitative analysis of the latent period of lung cancer induced by air pollutants.