title: [Comparative field study on high flow rate samplers for respirable fraction-A solution to smaller collected masses].
abstract: OBJECTIVE
  Dust sample mass gain is too smaller to satisfy the limit of detection (LOD) even in most cases during dust sampling at workplaces nowdays, especially for respirable fraction. Therefore, it is aimed to solve the problem by increasing sample load with high flow rate samplers.
  
  
  METHODS
  In A and B two shipyards respirable welding fume was sampled by high flow rate cyclone samplers of FSP-10 (10 L/min) for 2-2.5 hours and normal flow rate FSP-2 (2 L/min) for 3-4 hours with a stratigy of parallele sampling at the same workpalce, in order to compare their mass gain, coincidence rate with LOD, and airborn dust concentration.
  
  
  RESULTS
  Sample mass gain of 0.97±0.40 mg and 1.61±0.86 mg respectively in the two factories by FSP-10 was significantly higher than that of 0.29±0.12 mg and 0.51±0.27 mg by FSP-2 (t-test, P<0.05 in both cases) , increasing herewith the coincidence rate with LOD from 26.8% (when sampling with FSP-2, calculated together with samples of the two factories) to 89.7%. However there was no significant difference in dust concentrations by the two different samplers, 0.53±1.88 vs 0.73±1.61 mg/m(3) by FSP-2 and FSP-10 in the shipyard A and 1.14±1.78 vs 1.01±1.63 mg/m(3) in the factory B (t-test, P>0.05 in every case) . In addtion, sample loading by FSP-2 was found to be correlated to sampling time (R(2)=0.7906, y=0.002 6x) , therefore, it has to sample for ≥192.3 min to meet the LOD (0.5 mg) in case of normal flow rate.
  
  
  CONCLUSIONS
  By using of high flow rate cyclone FSP-10 the problem of LOD could be solved, along with increased sample mass and similar respirable dust concentration by the two samplers. Some techincal improvements of FSP-10 and increasing of LOD coincidence rate by other methods was also disscussed.
authors.affiliation: School of Public Health, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Limin
authors.initials: L
authors.lastname: Wang
authors.forename: Fengxia
authors.initials: F
authors.lastname: Hu
authors.forename: Zhenglun
authors.initials: Z
authors.lastname: Wang
authors.forename: Jiaojun
authors.initials: J
authors.lastname: Liang
authors.forename: Jichao
authors.initials: J
authors.lastname: Li
authors.forename: Geshi
authors.initials: G
authors.lastname: Mao
authors.forename: Wwili
authors.initials: W
authors.lastname: Song
authors.forename: Guilin
authors.initials: G
authors.lastname: Yi
authors.forename: Lei
authors.initials: L
authors.lastname: Zhao
authors.forename: Jiabing
authors.initials: J
authors.lastname: Wu
authors.forename: Michael
authors.initials: M
authors.lastname: Koob
authors.forename: Weihong
authors.initials: W
authors.lastname: Chen
authors.forename: Dirk
authors.initials: D
authors.lastname: Dahmann
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D060389:Construction Industry; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring / Q000295:instrumentation*; D016273:Occupational Exposure; D012767:Ships; D017132:Workplace
chemical_list: D000395:Air Pollutants, Occupational; D004391:Dust