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Human health concerns related to chronic exposure to raw sewage resulting from a malfunctioning sanitary sewer line.
(Follow-up to the Better Brite August 2002 Health Consultation)



The owner/proprietor of a small building and business in Chippewa Falls, Wisconsin, reported health problems possibly related to chronic exposure to untreated sewage. Exposure to sewage is a human health hazard. Inhalation exposure may have been increased by aerosolizing the sewage with a wet/dry vacuum. The Wisconsin Division of Public Health recommended that the sewer line be repaired immediately, that the property be assessed for microbial contamination, the occupants be medically evaluated for chronic effects of microbial exposure, and that affected surfaces within the building be disinfected.


The Wisconsin Division of Public Health (DPH) was contacted by the owner/proprietor of a small building and business in Chippewa Falls, Chippewa County, Wisconsin, regarding health symptoms that she suspected were related to exposure to raw sewage in her workplace. The health symptoms reported by the business owner included chronic malaise, fatigue, headache, heart palpitation, itchy scalp, ringing ears, memory loss, numbness on left side, loss of swallowing reflex, and muscle soreness (1). The owner reports that medical treatment to date has provided no diagnosis other than early emphysema. The business is located in a former residential building dating to the late 1800s. The owner described the problem of an obstructed sanitary sewer servicing the building, causing water and solids to well up from a basement sanitary sewer drain and accumulate on the basement floor. In attempting to clear the sewer line, a plumber's router tape had become irreversibly lodged, further obstructing the sewer line. Presently, excavation is the only available option to repair the line. A property access dispute between the building owner and a neighbor has prevented the sewer line from being repaired; the condition has persisted since July 1999 (1).

In the course of removing the accumulated sewer water using hand-held containers and a wet/dry vacuum, the building owner may have been exposed to microbial contaminants in the sewer water. The exposure would be either through skin contact with the handled sewage, accidental hand-to-mouth ingestion of contaminants, or through inhalation of aerosols of biological and chemical contaminants in the sewage.


Exposure to raw sewage is a human health hazard that should be interrupted without delay. DPH is particularly concerned about the infection potential following contact exposure while cleaning the sewage and the possibility that the use of a wet/dry vacuum creates bioaerosols. The exposure of bioaerosols to the business owner is predicted but has not been verified. Similarly, the exposure potential to patrons of this business requires further assessment of the workplace. Under the right conditions, exposure to bacterial aerosols are reported to cause health effects, including fever, cough, and dyspnea from high exposure to bacterial endotoxin.

Endotoxins are a group of lipopolysaccharides that are cell wall components of gram negative bacteria (GNB) (2). Inhalation exposure to GNB cell fragments produce both toxic and hypersensitivity effects. Some studies conclude that chronic inhalation of bacterial endotoxin causes chronic bronchitis, emphysema, and may be associated with airway hyperresponsiveness (3,4). Sources of airborne bacterial endotoxin include aerosols from contaminated water, contaminated heating and air-conditioning systems, mist-generating humidifiers, damp or water-damaged homes, and agricultural dusts (3).


Children are not routinely present at the business. If children are in the building, care must be taken not to allow them into the basement area. Children would be particularly susceptible to sewage bacteria.


  • Exposure to raw sewage is a public health hazard.
  • The case history predicts chronic, though unverified, exposure of the building occupants to raw sewage, through both inhalation and direct contact.
  • Chronic exposure to microbial contaminants in sewage has not been ruled out as a cause of the reported health complaints.
  • Repair of the sewer line and disinfection of affected surfaces is needed to mitigate exposure to raw sewage.


  • DPH recommends that the obstructed sanitary sewer be immediately repaired in order to mitigate exposure to raw sewage.
  • DPH recommends that the affected building be sampled for airborne- and surface-culturable biologicals, particularly gram-negative bacteria.
  • DPH recommends that specific health complaints be discussed with a physician qualified to evaluate the effects of chronic exposure to airborne biologics.
  • Following completion of the sewer repair, the building owner or their agent should disinfect sewage affected areas. This would include discarding sewage contaminated items in the basement, and cleaning affected building surfaces with disinfectant, such as a 3% bleach solution (4 oz. bleach per gallon water).


  • DPH has agreed to conduct sampling and forward the samples to the Wisconsin State Hygiene Laboratory.
  • The building owner has agreed to submit to a medical evaluation as recommended


  1. Private correspondence to the Agency for Toxic Substances and Disease Registry. DHAC/PER15B. February 28, 2002.
  2. Milton, DK. 1999. Endotoxin and other bacterial cell-wall components. Ch. 23 in (Macher, J, ed.) Bioaerosols: Assessment and Control. Am. Conf. Gov. Industrial Hygienists, Cinn. OH.
  3. Reed CE, Milton DK. 2001. Endotoxin-stimulated innate immunity: A contributing factor for asthma. J Allergy Clin Immunol 108:157-66.
  4. Klut ME, van Eeden SF, Whalen BA, Verburgt LM, English D, Hogg JC. 1996. Neutrophil activation and lung injury associated with chronic endotoxemia in rabbits. Exp Lung Res 22: 449-65.


Robert Thiboldeaux, Ph.D.
Toxicologist, Bureau of Environmental Health


This public health consultation/ exposure investigation for a business proprietor in Chippewa Falls Wisconsin was prepared by the Wisconsin Department of Health and Family Services under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the Public Health Consultation was begun.

Gail D. Godfrey
Technical Project Officer, S.P.S., SAAB, DHAC

The Division of Health Assessment and Consultation, ATSDR, has reviewed this Public Health Consultation and concurs with the findings.

Lisa C. Hayes
for Chief, State Program Section, DHAC, ATSDR

Table of Contents The U.S. Government's Official Web PortalDepartment of Health and Human Services
Agency for Toxic Substances and Disease Registry, 4770 Buford Hwy NE, Atlanta, GA 30341
Contact CDC: 800-232-4636 / TTY: 888-232-6348

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