IBRAHIM ADAM examines the growing public health threat posed by mould in residential buildings and other indoor environments, emphasising its ability to cause severe health damage and the urgent need for early detection and control
Barely a week after their wedding in November 2025, what was meant to be the beginning of a joyful new chapter for 24-year-old Fatima Usman and her husband, Kabir Usman, 32, began to unravel in ways they never imagined.
Fatima began sneezing frequently, followed by a persistent cough and severe headaches. At first, they thought it was normal, perhaps stress from the wedding.
“I didn’t want to take any chances. She had just moved into a new home, a new life. I felt it was my responsibility to make sure she was fine,” Kabir said.
At the hospital, Fatima was diagnosed with malaria after a test. The doctor prescribed medication and the young couple returned home.
But five weeks later, Fatima’s symptoms worsened, and Kabir began experiencing the same symptoms. They returned to the hospital and another round of tests confirmed malaria in both of them.
The doctor asked about their home and Kabir explained that he had secured the Lekki apartment three weeks before their wedding but had only spent two nights there when their health crisis started.
In January 2026, while cleaning the bedroom, Kabir discovered mould growing on the wall where his wife slept.
“I was cleaning the bedroom one Saturday in January. As soon as I pulled the bed aside, I noticed this black stain stretching from the headboard down the side of the wall where my wife faces sometimes when sleeping,” he said.
He called out to Fatima to ask if she had noticed the mould on the wall, even though they did not know the name.
“She said she had seen something like that on walls when visiting other people’s homes but did not know what it means or realise it was in their bedroom,” he said.
Kabir took pictures and sent them to their doctor, whose response was immediate. They were asked to visit the hospital without delay.
According to Kabir, the doctor identified the stain as black mould, a type of fungus that thrives in damp, poorly ventilated spaces.
“The doctor told us plainly that mould can be deadly if it remains in the house for too long. He explained that prolonged exposure to black mould can cause serious respiratory problems and other health complications. That was when everything started to make sense.
“All along, we were treating malaria, but we were sleeping every night in a room that was making us sick and could have even killed us. If we had not discovered it when we did, I do not know how much worse it could have become,” he said.
Teen dies from mould exposure
Sharing the image of 19-year-old Linda Okpara, a Facebook user, Okezie Agu, said the teenager died from respiratory complications caused by prolonged exposure to mould.
Agu wrote that Okpara, a 19-year-old indigene of Orlu in Imo State, passed away on 25 August 2025 due to complications from inhaling mould that had spread throughout the walls of her family home in Lugbe, Abuja.
He wrote that the photograph was sent to him by the deceased’s elder sister, who had earlier alerted him to the severe mould infestation in their residence.
“The painful thing is that even in this picture of the late girl, sent to me by her elder sister who alerted me about the severe mould situation in their house, she (Linda) was posing in front of a wall with visible dampness and mould.
“FG and relevant agencies, at what point will you swing into action to regulate and penalise landlords in Nigeria who collect exorbitant rent from tenants and abandon them in mould-infested houses? Ninety percent of Nigerians staying in rented houses in Abuja and Lagos have some level of mould growing on their walls, floors, and ceilings. In 40 per cent of these cases, the source of moisture comes from leaking pipes buried in the building,” Agu wrote.
He urged the Federal Government to provide supplementary safe housing for Nigerians to prevent citizens from residing in “mould-ravaged houses.”
“How many more Nigerians will have to fall ill and die like Linda before the government intervenes?” he queried.
Exposure to moulds
A medical laboratory scientist in training at Irrua Specialist Teaching Hospital, Edo State, Ifuhemi Olotu, described mould as a type of fungus that thrives in damp conditions and has become an unwelcome presence in cracked, waterlogged and poorly ventilated buildings.
Olotu explained that once mould spores are inhaled, occupants are exposed to a range of potential health complications.
“Exposure to mould can cause a range of health effects, including allergic reactions such as sneezing, runny nose, itchy eyes, and skin rashes. It can also lead to breathing problems, frequent headaches, throat irritation, sinus congestion, and skin or eye irritation.
“In some cases, mould exposure can cause infections, particularly in people with weakened immune systems. Children, elderly people and individuals with asthma or allergies are usually more affected and may experience stronger or more frequent symptoms,” she told Saturday .
A 2023 report by the Nigerian Environmental Society found that more than 62 per cent of households surveyed in urban slums in Lagos, Port Harcourt and Onitsha showed visible signs of mould in at least one room.
In the same survey, 38 per cent of families reported persistent respiratory symptoms among household members, which were most prevalent in communities characterised by poor housing infrastructure and inadequate drainage systems.
The World Health Organisation noted that exposure to indoor dampness and mould increases the risk of respiratory symptoms by between 30 and 50 per cent, particularly among children and individuals with existing health conditions.
The WHO added that illnesses linked to mould exposure range from nasal congestion and throat irritation to more serious conditions such as asthma, chronic bronchitis and fungal infections.
A 2022 study conducted by the Nigerian Thoracic Society reported a 44 per cent prevalence of asthma among children aged six to 12 who were exposed to indoor mould. By contrast, asthma prevalence stood at 18 per cent among children living in dry, mould-free homes.
The Centres for Disease Control and Prevention warned that exposure to damp and mouldy environments may cause a variety of health effects, although some individuals may experience none.
Consequences of misdiagnosis
A nurse at Abubakar Tafawa Balewa University Teaching Hospital in Bauchi State, Amina Ahmed, told Saturday that black mould, scientifically known as Stachybotrys chartarum, thrives in damp and water-damaged areas and can pose serious health risks when its spores are inhaled.
Ahmed noted that this type of mould requires warmth and moisture to grow, “Black mould needs warm temperatures and moisture to grow and spread. It commonly appears in damp or water-damaged areas of your home, such as basements, showers and windows.
“Black mould can also worsen asthma, causing wheesing, shortness of breath and chest tightness. Individuals with weakened immune systems are at higher risk of fungal infections affecting the airways or other parts of the body,” she said.
A clinical mycologist at the Abubakar Tafawa Balewa University Teaching Hospital, Bauchi State, Hassan Abdulkadir, warned that fungal infections caused by moulds can become life-threatening when misdiagnosed or treated incorrectly.
He explained that these infections are often mistaken for more common illnesses, despite being medical emergencies.
“Most patients present with symptoms that resemble pneumonia, sinusitis, or sepsis, and are immediately started on antibiotics. The main problem is that antibiotics do not kill fungal. Meanwhile, moulds such as Aspergillus fumigatus and Stachybotrys chartarum continue invading lung tissue and blood vessels,” he told Saturday .
“Infections caused by moulds in mucorales can escalate rapidly after steroid exposure, potentially leading to rapid tissue invasion, facial or sinus necrosis, spread to the brain, stroke, and death within days or weeks,” he added.
Mould takes over house
For Instagram user Twin Sandra (gbajumo_glitter), the place that should have offered comfort and safety instead became a constant source of anxiety and illness, as she faced a hidden danger that seemed impossible to control.
In the video, Sandra appeared visibly distressed and in tears as she described the serious toll the mould in her home had taken on her health.
She said every effort to maintain her home appeared to be undermined by the black mould, which slowly changed her daily life and her sense of security within the space
“The worst thing anyone can have in their house is mould. Mould can be very dangerous. Mould can kill you, it can render you useless, it can make you extremely sick and leave you feeling helpless. I constantly battle with mould in this house. I moved in last year February, during the rainy season, when I started noticing black mould growing,” she said.
She said she tried to address the problem as best she could, but the mould persisted and gradually took a toll on her health, leaving her frustrated and unsure which measures would actually make a difference.
“I tried to control it, but I couldn’t. Since then, I’ve been having ongoing health issues. In my entire life, I had never had a fungal infection, but then I developed one. I kept treating it over and over again. I used medication and followed the treatment carefully,” she explained.
Preventive measures
A Health, Safety and Environment laboratory officer at University of Lagos Consult Limited, Segun Gadimoh, has warned that houses located close to dumpsites expose residents, particularly women, to an increased risk of harmful mould.
Gadimoh explained that decomposing waste at dumpsites creates conditions that support mould growth, which can spread into nearby homes.
He noted that people living just a few metres away are frequently exposed to spores released into the air.
“Dump sites contain large amounts of decomposing organic waste, which creates damp and humid conditions that encourage the growth of mould and other fungi. People living only a few metres away may inhale these spores regularly or come into contact with them through contaminated surfaces,” he told Saturday .
He added that women face increased exposure through routine domestic activities, such as drying clothes outdoors, where spores can settle on fabrics.
A scientific officer at the Kebbi State Ministry of Health, Basiru Kwaifa, has warned that mouldy food in kitchens, particularly in fridges and cabinets, could serve as a hidden source of serious health problems for individuals and families.
“One of the most overlooked sources is your kitchen, especially mouldy food in your fridge and cabinets. Mould thrives in humidity, and your fridge can be the perfect breeding ground,” he told Saturday .
Kwaifa cautioned residents against the common practice of cutting off the visibly affected part of mouldy food while consuming the remainder, stressing that such actions may still expose them to harmful contamination.
“Many people think that if they remove the mouldy part, the remaining food is safe. But mould actually spreads and can exist in parts that look fine. It can also contaminate nearby foods even if they appear untouched,” he explained.
A certified paediatric nutritionist, Ify Omesiete, noted that recurring childhood illnesses affecting many families may be linked to mould spores that are most active at night.
Omesiete explained that conventional laboratory investigations, including routine blood tests, may fail to detect the presence of mould because it is fungal rather than bacterial or viral in nature, thereby complicating diagnosis and treatment.
“No matter how many full blood count tests you conduct, you will not detect mould in the results because it is not bacterial, it is fungal. That means antibiotics will not work,” she said.
She advised households to consider using dehumidifiers, air purifiers, or mould control devices, noting that placing such devices in different rooms can significantly reduce humidity and curb the spread of spores.
‘Inspect buildings carefully’
A wall failure expert, Barakat Adesina, identified non-compliance with proper building procedures as a leading cause of mould growth and dampness in residential buildings, which exposes occupants to health risks and financial losses.
Adesina told Saturday that mould should not be dismissed as a cosmetic issue but treated as a warning sign of deeper structural and environmental problems.
“Mould is not just a stain on your wall; it is a warning sign. The biggest problem today is that proper building methods, such as using damp-proof membranes or damp-proof courses, are often ignored. The sad part is that tenants suffer the most because many of these spaces are built primarily for rent,” she said.
Adesina advised prospective tenants to inspect buildings carefully for signs of dampness before committing to a property, noting that early detection could prevent long-term financial and health burdens.
“If you touch a wall and find water patches, or if it feels cold, take it seriously. Do not overlook these signs,” she said.