Mold Prevention Strategies and Possible Health Effects in the Aftermath of Hurricanes and Major Floods

Abstract

Extensive water damage after major hurricanes and floods increases the likelihood of mold contamination in buildings. This report provides information on how to limit exposure to mold and how to identify and prevent mold-related health effects. Where uncertainties in scientific knowledge exist, practical applications designed to be protective of a person's health are presented. Evidence is included about assessing exposure, clean-up and prevention, personal protective equipment, health effects, and public health strategies and recommendations. The recommendations assume that, in the aftermath of major hurricanes or floods, buildings wet for >48 hours will generally support visible and extensive mold growth and should be remediated, and excessive exposure to mold-contaminated materials can cause adverse health effects in susceptible persons regardless of the type of mold or the extent of contamination. Recent parallels to the kind of flooding observed in New Orleans as a result of hurricanes Katrina and Rita occurred in 1997 in Grand Forks, North Dakota, and in 1999 in North Carolina after Hurricane Floyd (2). The number of structures affected was much smaller in North Dakota than in New Orleans, and the population affected in North Carolina was much more dispersed than the population affected in New Orleans. In North Carolina, a reported increase in persons presenting with asthma symptoms was postulated to be caused by exposure to mold (2). In 2001, flooding and subsequent mold growth on the Turtle Mountain reservation in Belcourt, North Dakota was associated with self-reports of rhinitis, rash, headaches, and asthma exacerbation (3). Methods This document was initially prepared by CDC as a guide for public health officials and the general public in response to the massive flooding and the anticipated mold contamination of homes and other structures along the U.S. Gulf Coast associated with hurricanes Katrina and Rita (4). A workgroup was convened of CDC staff with expertise in relevant subject areas. This included medical epidemiologists, environmental epidemiologists and occupational epidemiologists, industrial hygienists, infectious disease physicians and mycologists. The framework for the document was decided by consensus discussions, and workgroup members were assigned to research and to write different sections. The members produced individual written summaries, which formed the basis of the report. Wherever possible, recommendations were based on existing recommendations or guidelines. Where adequate guidelines did not exist, the guidelines were based on CDC experience and expertise.

Satratoxin-G from the Black Mold Stachybotrys chartarum Induces Rhinitis and Apoptosis of Olfactory Sensory Neurons in the Nasal Airways of Rhesus Monkeys

“…One of the principal arguments against the hypothesis that S. chartarum causes adverse health effects in people is that the concentrations of Stachybotrys reported to cause toxicity in animal studies may not be achieved in water-damaged indoor air environments (Chapman et al 2003;Hossain et al 2004;Lai 2006). The total dose of SG used in the present study (20 mg) would represent exposure to a large number of Stachybotrys spores (2 Â 10 7 ) (Pestka et al 2008), which may only be encountered in heavily contaminated areas (Brandt et al 2006). However, SG is not only found in fungal spores, but is also present in viable and nonviable fungi and fungal fragments (Brasel et al 2005).…”

“…Satratoxin-equivalent concentrations ranging from 2 to 330 ng/m 3 have been estimated to occur in rooms of water-damaged homes heavily contaminated with S. chartarum (Vesper et al 2000;Yike et al 1999). Acute, shortterm exposure to high airborne concentrations of SG is likely to occur in heavily contaminated environments, or during processes that disrupt nutrient sources for mold, such as would occur during mold remediation procedures (Brandt et al 2006). However, adverse health effects have also been associated with sustained or repeated exposure to damp indoor environments that are contaminated with S. chartarum, as would be expected in the workplace, home, or school (Park and Cox-Ganser 2011).…”

Infectious diseases in the aftermath of monsoon flooding in Pakistan

“…Skin conditions related to this are particularly common, regardless of the type of mould or the extent of contamination [14] . In one study conducted in Thailand, it was found that eczema is the most common dermatosis during floods [15] .…”

“…According to estimates, over 1 600 people lost their lives in the resulting floods, with 14 million people across the region adversely affected [2,3] . Despite extensive relief and rescue operations, the death toll is expected to rise as thousands of people are still cut off from the rest of the country.…”

Effect of Gaseous Chlorine Dioxide on Indoor Microbial Contaminants

“…4 -6 There has been increased interest in the use of new technologies for the remediation of mold and bacteria, especially since the prolonged flooding after Hurricanes Katrina and Rita in the New Orleans area resulted in highly contaminated buildings. [7][8][9] Among several techniques, the generation of gaseous chlorine dioxide (ClO 2 ) is currently being explored for the remediation of structures that have been impacted by microbial growth. The advantage of using a gas is that it can penetrate into building cavities.…”