Exposure matrices of endotoxin, (1→3)-β-d-glucan, fungi, and dust mite allergens in flood-affected homes of New Orleans.
This study examined: (i) biocontaminant levels in flooded homes of New Orleans two years after the flooding; (ii) seasonal changes in biocontaminant levels, and (iii) correlations between biocontaminant levels obtained by different environmental monitoring methods. Endotoxin, (1→3)-β-d-glucan, fungal spores, and dust mite allergens were measured in 35 homes during summer and winter. A combination of dust sampling, aerosolization-based microbial source assessment, and long-term inhalable bioaerosol sampling aided in understanding exposure matrices. On average, endotoxin found in the aerosolized fraction accounted for <2% of that measured in the floor dust, suggesting that vacuuming could overestimate inhalation exposures. In contrast, the (1→3)-β-d-glucan levels in the floor dust and aerosolized fractions were mostly comparable, and 25% of the homes showed aerosolizable levels even higher than the dust-borne levels. The seasonal patterns for endotoxin in dust and the aerosolizable fraction were different from those found for (1→3)-β-d-glucan, reflecting the temperature and humidity effects on bacterial and fungal contamination. While the concentration of airborne endotoxin followed the same seasonal trend as endotoxin aerosolized from surfaces, no significant seasonal difference was identified for the concentrations of airborne (1→3)-β-d-glucan and fungal spores. This was attributed to the difference in the particle size; smaller endotoxin-containing particles can remain airborne for longer time than larger fungal spores or (1→3)-β-d-glucan-containing particles. It is also possible that fungal aerosolization in home environments did not reach its full potential. Detectable dust mite allergens were found only in dust samples, and more commonly in occupied homes. Levels of endotoxin, (1→3)-β-d-glucan, and fungi in air had decreased during the two-year period following the flooding as compared to immediate measurements; however, the dust-borne endotoxin and (1→3)-β-d-glucan levels remained elevated. No conclusive correlations were found between the three environmental monitoring methods. The findings support the use of multiple methods when assessing exposure to microbial contaminants.
Adhikari
Atin
A
Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267-0056, USA.
Lewis
Jocelyn Suzanne
JS
Reponen
Tiina
T
Degrasse
Enjoli C
EC
Grimsley
L Faye
LF
Chew
Ginger L
GL
Iossifova
Yulia
Y
Grinshpun
Sergey A
SA
D016902:Air Pollution, Indoor / Q000032:analysis* / Q000706:statistics & numerical data; D039741:Antigens, Dermatophagoides / Q000032:analysis*; D004391:Dust / Q000032:analysis; D004731:Endotoxins / Q000032:analysis*; D004784:Environmental Monitoring; D055868:Floods; D006798:Housing / Q000706:statistics & numerical data; D006813:Humidity; D019570:Inhalation Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D055820:New Orleans; D011509:Proteoglycans; D018570:Risk Assessment; D012621:Seasons; D013172:Spores, Fungal / Q000302:isolation & purification*; D013696:Temperature; D047071:beta-Glucans / Q000032:analysis*
D039741:Antigens, Dermatophagoides; D004391:Dust; D004731:Endotoxins; D011509:Proteoglycans; D047071:beta-Glucans; C010770:polysaccharide-K
Environ Health Perspect. 2006 Dec;114(12):1883-9
17185280
Pediatr Allergy Immunol. 2006 Sep;17(6):450-7
16925691
Clin Rev Allergy. 1990 Spring;8(1):31-49
2180540
Sci Total Environ. 2006 Dec 1;371(1-3):31-43
17049968
Ann Occup Hyg. 2003 Apr;47(3):187-200
12639832
Clin Exp Allergy. 1999 Apr;29(4):470-7
10202361
J Occup Environ Hyg. 2006 May;3(5):262-73
16595378
Environ Health Perspect. 2006 Sep;114(9):1381-6
16966092
Appl Environ Microbiol. 2002 Jul;68(7):3522-31
12089037
Environ Health Perspect. 1999 Jun;107 Suppl 3:501-3
10346999
J Allergy Clin Immunol. 1995 Sep;96(3):325-33
7560634
Sci Total Environ. 2009 Jan 1;407(2):806-14
19012949
Indoor Air. 2004 Dec;14(6):405-12
15500633
Ann Agric Environ Med. 2004;11(2):269-77
15627336
J Allergy Clin Immunol. 2006 May;117(5):1082-9
16675336
J Allergy Clin Immunol. 1992 Sep;90(3 Pt 1):292-300
1527314
Environ Res. 2008 Mar;106(3):401-9
18199434
J Allergy Clin Immunol. 1992 Mar;89(3):752-9
1545096
Sci Total Environ. 2004 Aug 15;329(1-3):75-86
15262159
Appl Environ Microbiol. 2007 Mar;73(5):1630-4
17209066
Environ Res. 2009 Apr;109(3):215-24
19201399
Immunol Allergy Clin North Am. 2003 Aug;23(3):519-31
14524389
Allergy. 2007 May;62(5):504-13
17441791
Atmos Environ (1994). 2007 Dec;41(37):8140-8149
19050738
Environ Sci Technol. 2007 Apr 1;41(7):2401-6
17438793
Am J Respir Crit Care Med. 1998 Nov;158(5 Pt 1):1685-7
9817726
J Immunol Methods. 1989 Mar 31;118(2):227-35
2926155
Appl Environ Microbiol. 2008 Feb;74(3):585-93
18065630
Inflamm Res. 2001 May;50(5):254-61
11409488