PMID- 32793876
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20240329
IS  - 2589-9147 (Electronic)
IS  - 2589-9147 (Linking)
VI  - 9
DP  - 2020 Dec 1
TI  - An overlooked route of inhalation exposure to tap water constituents for children 
      and adults: Aerosolized aqueous minerals from ultrasonic humidifiers.
PG  - 100060
LID - 10.1016/j.wroa.2020.100060 [doi]
LID - 100060
AB  - Fine particulates and aerosols emitted by commonly used, room-sized ultrasonic 
      humidifiers may pose adverse health effects to children and adults. The 
      literature documents adverse effects for children exposed to minerals emitted 
      from humidifiers. This study performs novel and comprehensive characterization of 
      bivariate particle size and element concentrations of emitted airborne aerosols 
      and particles from ultrasonic humidifiers filled with tap water, including size 
      distribution from 0.014 to 10 mum by scanning mobility particle sizer and 
      AeroTrak; corresponding metal and elemental concentrations as a function of 
      particle size by inductively coupled plasma mass spectrometer; and calculations 
      of deposition fraction in human lungs for age-specific groups using the 
      multi-path particle dosimetry model (MPPD). Deposition fraction is the ratio of 
      mass deposited to total mass inhaled. When filled with tap water, water 
      evaporated from emitted aerosols to form submicron particles that became 
      essentially "dried tap water" with median size 146 nm and mean concentration of 
      211 mug-total elements/m(3)-air including 35 mug-calcium/m(3)-air in a room of 
      33.5 m(3) and air exchange rate at  approximately 0.8 hr(-1). Approximately 90% of emitted 
      particles deposited in human lungs were <1 mum as shown by MPPD model. The smaller 
      particles contained little water and higher concentration of minerals, while 
      larger particles of >1 mum consisted of lower elemental concentrations and more 
      water due to low evaporation. Deposition fraction in pulmonary region was  approximately 2-fold 
      higher, and deposited particulate mass was 3.5-fold higher for children than 
      adults, indicating greater inhalation exposure to children compared to adults. 
      Modeled data of total particles mass per body weight (BW) that will deposit in 
      adult and child lungs after 8-h humidifier exposure were respectively 2.8 
      mug/kg-BW and 9.8 mug/kg-BW, where calcium contributes 0.4 mug/kg-BW and 1.6 
      mug/kg-BW. This comprehensive study of bivariate inorganic chemical composition as 
      a function of particle size expanded, quantified, and modeled exposure for 
      children and adults to aerosolized calcium and other inorganic constituents in 
      water.
CI  - (c) 2020 The Authors. Published by Elsevier Ltd.
FAU - Yao, Wenchuo
AU  - Yao W
AD  - Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 
      USA.
FAU - Gallagher, Daniel L
AU  - Gallagher DL
AD  - Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 
      USA.
FAU - Dietrich, Andrea M
AU  - Dietrich AM
AD  - Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 
      USA.
LA  - eng
PT  - Journal Article
DEP - 20200728
PL  - England
TA  - Water Res X
JT  - Water research X
JID - 101742109
PMC - PMC7408721
OTO - NOTNLM
OT  - CMD, count median diameter
OT  - GSD, geometric standard deviation
OT  - ICP-MS, inductively coupled plasma mass spectrometry
OT  - Indoor air quality
OT  - Inhalation exposure
OT  - MPPD, multiple-path particle dosimetry
OT  - Metal exposure
OT  - Particulate matter
OT  - SMPS, scanning mobility particle sizer
OT  - Ultrasonic humidifier
COIS- The authors declare that they have no known competing financial interests or 
      personal relationships that could have appeared to influence the work reported in 
      this paper.
EDAT- 2020/08/15 06:00
MHDA- 2020/08/15 06:01
PMCR- 2020/07/28
CRDT- 2020/08/15 06:00
PHST- 2020/03/21 00:00 [received]
PHST- 2020/07/03 00:00 [revised]
PHST- 2020/07/24 00:00 [accepted]
PHST- 2020/08/15 06:00 [entrez]
PHST- 2020/08/15 06:00 [pubmed]
PHST- 2020/08/15 06:01 [medline]
PHST- 2020/07/28 00:00 [pmc-release]
AID - S2589-9147(20)30020-7 [pii]
AID - 100060 [pii]
AID - 10.1016/j.wroa.2020.100060 [doi]
PST - epublish
SO  - Water Res X. 2020 Jul 28;9:100060. doi: 10.1016/j.wroa.2020.100060. eCollection 
      2020 Dec 1.