For decades, landlords and their insurers have defended mold injury claims with one argument. They say that no reliable science can show that mold caused a particular person's illness. A 2026 article in the Cumberland Law Review takes that argument apart. Its title states its conclusion: Toxic Mold Litigation: Causation Should No Longer Be Controversial, 56 Cumb. L. Rev. 221 (2026).
The author, Vanessa L. Johnson, is an Associate Professor of Legal Studies at the University of Houston-Clear Lake, with law degrees in tax and health law. She reviews the research in immunology, toxicology and environmental medicine. She concludes that the scientific community now recognizes mold and its toxins as capable of causing illness across many body systems, through biological mechanisms that researchers can identify and measure.
Professor Johnson begins with the reports that defendants cite most. In 2004, the Institute of Medicine (IOM) found sufficient evidence of an association between damp indoor spaces and respiratory problems, including cough, wheeze, asthma flare-ups and upper respiratory symptoms. In 2009, the World Health Organization (WHO) confirmed those findings and added asthma development, shortness of breath and respiratory infections.
The WHO limited its review to respiratory outcomes. It set aside studies of the skin, eyes, nervous system and other organs, the article explains, because that research was not yet mature, not because anyone had disproven those effects. The research has since caught up. A 2020 review by Ming Dooley and Dr. Scott McMahon examined 114 studies published from 2011 through 2018, involving more than 73,000 participants on four continents.
Of those 114 studies, 112, or 98 percent, found statistically significant links between damp buildings and adverse health effects. Twenty-seven of them studied systems beyond the lungs, including neurological, digestive, musculoskeletal, cognitive and skin effects. Professor Johnson argues that this record defeats the claim that no reliable science supports mold-related illness. The National Institute of Environmental Health Sciences, part of the National Institutes of Health, likewise links mold exposure to allergic reactions, memory loss, depression and anxiety.
The article highlights a caveat in the 2004 IOM report that rarely surfaces in court. The IOM stated that its conclusions did not apply to people with weakened immune systems, who face greater risk of fungal infection. The WHO acknowledged the same vulnerability. Those reports therefore described healthy adults, not the people most likely to suffer serious harm from a moldy home.
Professor Johnson then reviews research showing that mold exposure can itself disturb the immune system. A 2015 study by Dr. Jamie Rosenblum Lichtenstein and colleagues compared blood cells from 33 mold-exposed patients with 17 controls. It found that chronic exposure altered the chemical signals immune cells use to coordinate a defense, which could weaken the body's ability to fight infection and other challenges.
Other work points the same way, though some of it remains small. Physicians reported antibodies linked to autoimmune disease in patients exposed to water-damaged buildings. A 2022 pilot study of six office workers found an immune-suppressing mold compound in the urine of two who took no such medication. The article argues that a weakened immune system can be both a risk factor for mold illness and a result of it.
The article's central point is that the focus belongs on mycotoxins, the toxic compounds certain molds produce. Researchers have identified more than 500 of them. Mycotoxins can remain in a home after the mold that made them has died, and one species can produce several. Professor Johnson argues that these toxins, rather than the spores themselves, cause much of the harm.
Science has studied mycotoxins for decades because they contaminate food. A joint expert committee of the WHO and the Food and Agriculture Organization sets tolerable intake levels for many of them. By the article's calculation, a 154-pound adult reaches the weekly limit for ochratoxin A at about 7.8 micrograms, an amount invisible to the eye. Research links aflatoxins to liver cancer, ochratoxin A to kidney damage, and trichothecenes from Stachybotrys to tissue damage.
Breathing these toxins may matter more than swallowing them, the article notes, because the lungs deliver them into the bloodstream without first passing through the liver. Modern laboratory tools, including mass spectrometry and polymerase chain reaction (PCR), can now identify and measure mold and mycotoxins both in a home and in a person. Matching the two, interpreted by a qualified toxicologist and paired with a careful differential diagnosis, supplies case-specific proof of exposure and injury. You can read more in our article on the biological match.
Maryland judges screen expert testimony under Maryland Rule 5-702 and Rochkind v. Stevenson, 471 Md. 1 (2020), which asks whether an expert's method rests on reliable, tested and accepted science. Professor Johnson's article shows that the link between damp, moldy buildings and respiratory illness is well established. She argues that the evidence for wider, multi-system illness now meets the civil standard of more likely than not.
The article does not claim every mold case wins. It acknowledges that courts and medical organizations have criticized certain diagnoses and laboratory tests. It cites Chesson v. Montgomery Mutual Insurance Co., 434 Md. 346 (2013), in which Maryland's highest court rejected testimony resting on a contested diagnostic method. Strong cases pair proof of the mold with a physician's careful examination that rules out other causes. That proof may come from laboratory testing, or, where no testing exists, from an expert who identifies the mold in photographs, videos and the home itself, a housing inspector's citation, or the acknowledgment of the landlord's own employees.
To discuss a Maryland mold injury claim, e-mail chris@attorneybeard.com or call (410) 267-0227.
