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Dietrich AM, Yao W, Gohlke JM, Gallagher DL. Environmental risks from consumer products: Acceptable drinking water quality can produce unacceptable indoor air quality with ultrasonic humidifier use. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:158787. [PMID: 36116655 DOI: 10.1016/j.scitotenv.2022.158787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/10/2022] [Accepted: 09/11/2022] [Indexed: 06/15/2023]
Abstract
The commonly used consumer product of an ultrasonic humidifier (e.g., cool mist humidifier) emits fine particles containing metals from tap water used to fill the humidifier. The objectives are: 1) predict emitted indoor air inhalable metal concentrations produced by an ultrasonic humidifier filled with tap-water containing As, Cd, Cr, Cu, Mn, and Pb in 33 m3 or 72 m3 rooms with varying air exchange rates; 2) calculate daily ingestion and 8-h inhalation average daily dose (ADD) and hazard quotient (HQ) for adults and children (aged 0.25-6 yr); and 3) quantify deposition in respiratory tract via multi-path particle dosimetry (MPPD) model. Mass concentrations of indoor air metals increase proportionally with aqueous metal concentrations in fill water, and are inversely related to ventilation. Inhalation-ADDs are 2 magnitudes lower than ingestion-ADDs, using identical water quality for ingestion and fill-water. However, in the 33 m3, low 0.2/h ventilated room, inhalation-HQs are >1 for children and adults, except for Pb. HQ inhalation risks exceed ingestion risks at drinking water regulated levels for As, Cd, Cr, and Mn. MPPD shows greater dose deposits in lungs of children than adults, and 3 times greater deposited doses in a 33 m3 vs 72 m3 room. Rethinking health effects of drinking water and consumer products to broaden consideration of multiple exposure routes is needed.
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Affiliation(s)
- Andrea M Dietrich
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
| | - Wenchuo Yao
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Julia M Gohlke
- Department of Population Health Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Daniel L Gallagher
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
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Dietrich AM, Yao W, Gallagher DL. Exposure at the indoor water-air interface: Fill water constituents and the consequent air emissions from ultrasonic humidifiers: A systematic review. INDOOR AIR 2022; 32:e13129. [PMID: 36437646 PMCID: PMC9828259 DOI: 10.1111/ina.13129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/24/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
This systematic review investigates the emissions from ultrasonic humidifiers (e.g., cool mist humidifiers) within indoor air environments, namely soluble and insoluble metals and minerals as well as microorganisms and one organic chemical biocide. Relationships between ultrasonic humidifier fill water quality and the emissions in indoor air are studied, and associated potential adverse health outcomes are discussed. Literature from January 1, 1980, to February 1, 2022, was searched from online databases of PubMed, Web of Science, and Scopus to produce 27 articles. The results revealed clear positive proportional relationships of the concentration of microorganisms and soluble metals/minerals between fill water qualities and emitted airborne particles, for both microbial (n = 9) and inorganic (n = 15) constituents. When evaluating emissions and the consequent health outcomes, ventilation rates of specific exposure scenarios affect the concentrations of emitted particles. Thus, well-ventilated rooms may alleviate inhalation risks when the fill water in ultrasonic humidifiers contains microorganisms and soluble metals/minerals. Case reports (n = 3) possibly due to the inhalation of particles from ultrasonic humidifier include hypersensitivity pneumonitis in adults and a 6-month infant; the young infant exhibited nonreversible mild obstructive ventilator defect. In summary, related literature indicated correlation between fill water quality of ultrasonic humidifier and emitted particles in air quality, and inhalation of the emitted particles may cause undesirable health outcomes of impaired respiratory functions in adults and children.
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Affiliation(s)
- Andrea M. Dietrich
- Department of Civil and Environmental EngineeringVirginia TechBlacksburgVirginiaUSA
| | - Wenchuo Yao
- Department of Civil and Environmental EngineeringVirginia TechBlacksburgVirginiaUSA
| | - Daniel L. Gallagher
- Department of Civil and Environmental EngineeringVirginia TechBlacksburgVirginiaUSA
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Yao W, Gallagher DL, Gohlke JM, Dietrich AM. Children and adults are exposed to dual risks from ingestion of water and inhalation of ultrasonic humidifier particles from Pb-containing water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 791:148248. [PMID: 34139495 DOI: 10.1016/j.scitotenv.2021.148248] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 06/12/2023]
Abstract
Room-sized ultrasonic humidifiers are exposure pathways to aerosolized metals, with dose positively associated with increased concentrations of metals in fill water. This study innovatively quantifies water ingestion along with inhalation doses from humidifiers for 10-1000 μg/L dissolved lead (Pb) in tap water. The subsequent indoor air Pb concentrations, average daily doses, and inhalation deposited respiratory fractions were predicted under four room scenarios for 3-mo, 12-mo, 28-mo, and 6-yr children and adults. Elevated blood Pb levels (BLLs) in children were modeled using USEPA's Integrated Exposure Uptake Biokinetic (IEUBK) model. Indoor air Pb exceeds the USEPA ambient air standard of 0.15 μg/m3 when humidifier fill water contains 33 μg/L Pb in the small room of 33.5 m3 and 0.2 h-1 air exchange rate (AER). For this room, ~40-46% inhaled Pb-containing humidifier particles deposit in children's respiratory tracts; inhaling humidifier particles from ≥500 μg/L Pb water results in >1 μg/dL BLL in 2-7 yr children. For adults, ~23% of particles deposit in the respiratory tract; 8-h inhalation exposure with ≥17 μg/L Pb water exceeds the California EPA reproductive toxicity guideline of 0.5 μg/day. Larger rooms and higher AER decrease Pb inhalation exposure under the same water Pb concentration.
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Affiliation(s)
- Wenchuo Yao
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Daniel L Gallagher
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Julia M Gohlke
- Department of Population Health Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Andrea M Dietrich
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
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Lau CJ, Loebel Roson M, Klimchuk KM, Gautam T, Zhao B, Zhao R. Particulate matter emitted from ultrasonic humidifiers-Chemical composition and implication to indoor air. INDOOR AIR 2021; 31:769-782. [PMID: 33108019 DOI: 10.1111/ina.12765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 10/04/2020] [Accepted: 10/16/2020] [Indexed: 05/04/2023]
Abstract
Household humidification is widely practiced to combat dry indoor air. While the benefits of household humidification are widely perceived, its implications to the indoor air have not been critically appraised. In particular, ultrasonic humidifiers are known to generate fine particulate matter (PM). In this study, we first conducted laboratory experiments to investigate the size, quantity, and chemical composition of PM generated by an ultrasonic humidifier. The mass of PM generated showed a correlation with the total alkalinity of charge water, suggesting that CaCO3 is likely making a major contribution to PM. Ion chromatography analysis revealed a large amount of SO42- in PM, representing a previously unrecognized indoor source. Preliminary results of organic compounds being present in humidifier PM are also presented. A whole-house experiment was further conducted at an actual residential house, with five low-cost sensors (AirBeam) monitoring PM in real time. Operation of a single ultrasonic humidifier resulted in PM2.5 concentrations up to hundreds of μg m-3 , and its influence extended across the entire household. The transport and loss of PM2.5 depended on the rate of air circulation and ventilation. This study emphasizes the need to further investigate the impact of humidifier operation, both on human health and on the indoor atmospheric chemistry, for example, partitioning of acidic and basic compounds.
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Affiliation(s)
- Chester J Lau
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Max Loebel Roson
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Keifer M Klimchuk
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Tania Gautam
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Boyang Zhao
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Ran Zhao
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
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Carneiro R, Duncan S, O'Keefe S, Yu D, Huang H, Yin Y, Neill C, Zhang B, Kuhar T, Rideout S, Reiter M, Ross J, Chen P, Gillen A. Utilizing Consumer Perception of Edamame to Guide New Variety Development. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2021. [DOI: 10.3389/fsufs.2020.556580] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Consumption of edamame (vegetable soybeans) has increased significantly in the U.S. over the last 20 years. Although market demand has been increasing, most edamame is still imported from Asian countries. A team of multistate plant-breeding programs in the mid-Atlantic and Southeast U.S. has focused on developing new breeding lines that grow well in the U.S. and deliver what domestic growers, processors and consumers need and expect from their edamame. In our study, sensory evaluation was used to identify edamame genotypes and sensory attributes preferred by consumers to support breeding selection criteria. In the first year (reported as our “screening study”), 20 edamame genotypes were grown in three locations: Newport, AR, and Blacksburg and Painter, VA. In the second year (reported as our “validation study”), 10 edamame genotypes selected after our screening study were grown in Blacksburg and Painter, VA, Portageville, MO, and Stoneville, MS. In both years of research, untrained participants (adults; vegetable consumers not allergic to soy; N ≥ 50) used a traditional 9-point acceptability (hedonic) scale (1 = “dislike extremely”; 9 = “like extremely”) to evaluate overall-liking, aroma, appearance, taste, and texture, and a 5-point scale (1 = “not sweet,” 5 = “extremely sweet”) to evaluate sweetness intensity. Next, participants used a check-all-that-apply (CATA) list of selected sensory terms to describe the sensory characteristics of each edamame sample. Overall acceptability of edamame genotypes was significantly different among all genotypes (p < 0.05). Samples described as “bitter,” “sour” (flavor) or “starchy” (texture) were associated with lower acceptability scores while “salty” and “sweet” (flavor) were correlated with higher acceptability. Sensory data from the screening study were used to select the best genotypes by use of a defined decision process based on the consumer data. The validation study tested the selection decisions and further supported the genotype choices. Sensory evaluation is a powerful tool to direct breeders to improve market acceptability and develop new edamame genotypes. Both screening and validation studies illustrate the significant role of consumer sensory data in support of genotypes targeted for domestic (U.S.) production.
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Yao W, Gallagher DL, Dietrich AM. An overlooked route of inhalation exposure to tap water constituents for children and adults: Aerosolized aqueous minerals from ultrasonic humidifiers. WATER RESEARCH X 2020; 9:100060. [PMID: 32793876 PMCID: PMC7408721 DOI: 10.1016/j.wroa.2020.100060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 07/03/2020] [Accepted: 07/24/2020] [Indexed: 05/06/2023]
Abstract
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 μm 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 μg-total elements/m3-air including 35 μg-calcium/m3-air in a room of 33.5 m3 and air exchange rate at ∼0.8 hr-1. Approximately 90% of emitted particles deposited in human lungs were <1 μm as shown by MPPD model. The smaller particles contained little water and higher concentration of minerals, while larger particles of >1 μm consisted of lower elemental concentrations and more water due to low evaporation. Deposition fraction in pulmonary region was ∼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 μg/kg-BW and 9.8 μg/kg-BW, where calcium contributes 0.4 μg/kg-BW and 1.6 μg/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.
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Affiliation(s)
- Wenchuo Yao
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Daniel L. Gallagher
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Andrea M. Dietrich
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
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Yao W, Dal Porto R, Gallagher DL, Dietrich AM. Human exposure to particles at the air-water interface: Influence of water quality on indoor air quality from use of ultrasonic humidifiers. ENVIRONMENT INTERNATIONAL 2020; 143:105902. [PMID: 32623220 DOI: 10.1016/j.envint.2020.105902] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/13/2020] [Accepted: 06/15/2020] [Indexed: 05/22/2023]
Abstract
Ultrasonic humidifiers provide indoor relief to symptoms caused by dry air and produce aerosols containing both water and minerals that are present in the water that fills the humidifier. This study investigated the spatial distributions, concentrations, and metal and mineral composition of aerosols emitted when an ultrasonic humidifier was filled with deionized water (DI), low mineral tap water (LL), high total dissolved solids (TDS)/high hardness water (HH), and high TDS/low hardness water (HL). Aerosol/particle sizes and counts were obtained at six horizontal distances in both the plume and near floor for each water quality. Results are that water quality significantly affects particle size distributions which become uniform after 0.9 m from the humidifier outlet, and are independent of vertical distance from the humidifier. The mean count median diameters were 64 nm for DI, 129 nm for LL, 234 nm for HH, and 260 nm for HL; the particle counts and total mineral solids concentrations were 2,194 #/cm3 (16 µg/m3) for DI, 21,070 #/cm3 (113 µg/m3) for LL, 38,353 #/cm3 (438 µg/m3) for HH, and 43,880 #/cm3 (521 µg/m3) for HL. The µg/m3 values for LL, HH, and HL exceeded PM2.5 ambient air standards. Model predictions are that the deposition mass in the human respiratory system from inhaling particles emitted from HH and HL water exceed 135 µg for a 1 to 3-month old child and 600 µg for an adult over an 8-hr period. Mineral water quality significantly affects the distribution and concentration of emitted and inhaled indoor air particles. Consumers may unknowingly be degrading their indoor air quality when using tap water of acceptable drinking water quality as humidifier fill water.
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Affiliation(s)
- Wenchuo Yao
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Rachael Dal Porto
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA, USA; Department of Civil Engineering and Department of Chemistry, California State University, Sacramento, Sacramento, CA, USA
| | - Daniel L Gallagher
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Andrea M Dietrich
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
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