Monitoring of hospital emergency room visits as a method for detecting health effects of environmental exposures

We excerpted from the logs of the adult and children's emergency room at Soroka Hospital Medical Center the number and types of services requested by day for the year 1980. Both total visits and visits for respiratory conditions were examined in order to test whether rain, heat, or pollutants led to increased requests for emergency room care. The total visits for adults were 72,375, of which 1,727 (2.4%) were for selected respiratory conditions. The total visits for children were 19,232, and respiratory conditions were 3,980 (20.7%). There is marked seasonal excess for respiratory visits for children in winter, and a lesser excess for adult respiratory conditions. Non-respiratory conditions and overall visits are higher in summer months. Fewer visits occur on Saturday and on Friday, with the maximum on Sunday. Otitis and bronchitis among children show little day-of-week trends. "High event" days for admissions are determined by fitting a Poisson distribution to the numbers of admissions by day for various respiratory complaints, and we then examine the concordance between these high event days and days with rain, high pollution or temperature. Adult respiratory conditions were more likely to occur on days with high total particulates (TSP) and "respirable" particulates (RSP). When the mean values of RSP and TSP for high asthma and shortness of breath days were compared with a random day for the same month, significant differences were found for RSP for adults, but not for TSP. Natural dust is the more likely cause of this association. Emergency room monitoring should be useful in locations with high levels of man-made pollutants.