Prevalence of Building Dampness

Prevalence of Building Dampness

In 2009, 9.9% of U.S. homes had water damage from exterior leakage, while 8.1% had water damage from interior leakage based on data from the American Housing Survey of the U.S. Census. However, the survey did not cover dampness or mold. There is otherwise no national database on the prevalence of dampness and mold in U.S. houses; however, Table 1 below compiles data from studies that reported prevalence of various moisture-related conditions in U.S. houses.

There is considerable variation in the prevalence estimates for each of the indicated moisture categories. For the “any dampness or mold category”, four of the studies report the prevalence to be 50% or more, while three report prevalence values below 50%. The largest study (Spengler, 1994) reports prevalence of dampness and mold in 50% of the homes. Excluding the Freeman study because it only included bathrooms, the population weighted average prevalence of dampness or mold from these studies is 47% in the U.S.

Table 1. Reported prevalence of dampness and mold in U.S. houses.

Author

Location

Population (housing units)

Prevalence

Mold or mildew

Water damage or dampness

Basement water

Any dampness or mold

Brunekreef 1989 [1]

6 U.S. cities

4625

30%

17%

32%

55%

Chiaverini 2003 [2]

Rhode Island

2600

 

18%

 

23%

Freeman 2003 [3]

New Jersey

4291 (Hispanic)

 

 

 

17% (in bathroom)

Hu 1997 [4]

Los Angeles &

San Diego

2041

8%

 

 

 

Maier 1997 [5]

Seattle

925

54%

20%

22%

68%

Slezak 1998 [6]

Chicago

910 (Head Start)

 

 

 

16%

Spengler 1994 [7]

24 cities in U.S. & Canada

12,842

36%

24%

20%

50%

Stark 2003 [8]

Boston

492

38%

34%

 

52%

Population weighted average

 

 

33%

22%

23%

47%*

* Population weighted average excludes Freeman (2003) because it only considered bathrooms

Much less data are available on the prevalence rates of dampness in other types of buildings. The largest identified data set for dampness in offices is from a survey by the U.S. Environmental Protection Agency of 100 representative public and commercial U. S. office buildings. Table 2 provides data on the prevalence of past water damage and current water leaks from this survey [9]. Eighty five percent of buildings had past water damage and 45% had current water leaks. For U.S. schools, a survey by the General Accounting Office reported that 30% of schools had plumbing problems and 27% had roof problems [10]; however, the nature of the problems were not described so the prevalence of associated dampness and mold cannot be determined. Many small studies have documented dampness problems in schools [11].

 

Table 2. Prevalence of past water damage and current water leaks from a survey of 100 representative U.S. office buildings [9].

 

Total Prevalence

Basement

Roof

Mechanical Rooms

Occupied Space

Past Water Damage

85%

28%

50%

17%

71%

Current Leaks

45%

13%

15%

3%

34%

1.         Brunekreef, B., et al., Home dampness and respiratory morbidity in children. Am Rev Respir Dis, 1989. 140(5): p. 1363-7. https://dx.doi.org/10.1164/ajrccm/140.5.1363.

2.         Chiaverini, L.C., J.E. Hesser, and J.P. Fulton, Damp housing conditions and asthma in Rhode Island. Med Health R I, 2003. 86(5): p. 151-3.

3.         Freeman, N.C., D. Schneider, and P. McGarvey, Household exposure factors, asthma, and school absenteeism in a predominantly Hispanic community. J Expo Anal Environ Epidemiol, 2003. 13(3): p. 169-76. https://dx.doi.org/10.1038/sj.jea.7500266.

4.         Hu, F.B., et al., An epidemiological study of asthma prevalence and related factors among young adults. J Asthma, 1997. 34(1): p. 67-76. https://dx.doi.org/10.3109/02770909709071205.

5.         Maier, W.C., et al., Indoor risk factors for asthma and wheezing among Seattle school children. Environ Health Perspect, 1997. 105(2): p. 208-14. https://dx.doi.org/10.1289/ehp.97105208.

6.         Slezak, J.A., et al., Asthma prevalence and risk factors in selected Head Start sites in Chicago. J Asthma, 1998. 35(2): p. 203-12. https://dx.doi.org/10.3109/02770909809068208.

7.         Spengler, J.D., et al., Respiratory symptoms and housing characteristics. Indoor Air, 1994. 4(2): p. 72-82. https://dx.doi.org/10.1111/j.1600-0668.1994.t01-2-00002.x.

8.         Stark, P.C., et al., Fungal levels in the home and lower respiratory tract illnesses in the first year of life. Am J Respir Crit Care Med, 2003. 168(2): p. 232-7. https://dx.doi.org/10.1164/rccm.200207-730OC.

9.         Girman, J.R., B.J. Baker, and L.E. Burton, Prevalence of potential sources of indoor air pollution in U.S. office buildings, in Proceedings of Indoor Air 2002. 2002, Indoor Air 2002, Inc.: Monterey, California. p. 438-443 Available from: https://www.epa.gov/indoor-air-quality-iaq/prevalence-potential-sources-indoor-air-pollution-us-office-buildings.

10.       GAO, School facilities: condition of America's schools. 1995, General Accounting Office: Washington, D.C. Available from: https://www.gao.gov/products/HEHS-95-61.

11.       Mudarri, D. and W.J. Fisk, Public health and economic impact of dampness and mold. Indoor Air, 2007. 17(3): p. 226-235. https://dx.doi.org/10.1111/j.1600-0668.2007.00474.x.