Difference between filtering-type bulk and wet-only data sets based on site classification

In order to clarify the limitations and the effectiveness of filtering-type bulk sampler, a study on precipitation collected by filtering-type bulk and wet-only samplers was performed. At an urban site, there was a statistically significant difference between the filtering-type bulk and wet-only samples at a 1% significance level in the pH and major chemical components. At a suburban site, pH, NH4+, and nss-Ca2+ showed a difference at a 1% significance level and NO3- at a 5% significance level, but nss-SO42- did not show any difference even at a 5% significance level. At a 4 rural site, although there was a difference in nss-Ca2+ at a 1% significance level and in pH at a 5% significance level, nss-SO42-, NO3-, and NH4+ did not show any difference. The attributions of the deposition of gaseous compounds and and particulate matter in a filtering-type bulk sampler were estimated to be 32% (nss-SO42-), 46% (NO3-), 36%(NH4+), and 75% (nss-Ca2+) at an urban site, 14% (nss-SO42-), 16% (NO3-), 27% (NH4+), and 42% (nss-Ca2+) at a suburban site, and 16% (nss-SO42-), 17% (NO3-),19% (NH4+), and 47% (nss-Ca2+) at a rural site. The degree of pollution at a sampling site should be taken into account when using a data set collected with filtering-type bulk samplers. (C) 2003 Elsevier Science Ltd. All rights reserved.