It’s something everyone dreads spotting in their home or on their leftovers — mold.
The microscopic organism can invade any surface that is damp or moist, from shower curtains, to sinks, refrigerators and even air conditioning units.
Experts say you shouldn’t beat yourself up if there are only little bits of mold, and can instead just discard rotten food or wipe surfaces without suffering a health impact.
But Dr Nik Money, a fungal microbiologist who has spent decades researching mold, told DailyMail.com homeowners should be alarmed if the moldy area is larger than a pizza box — about one square foot. Then you’re likely to suffer health problems.
He warned mold covering an area this large would release a high amount of spores into the air, which could be breathed in and enter the lungs, leading to symptoms including coughing and trouble breathing.
Some experts have even suggested mold in homes may be linked to cognitive issues and depression.
Mold is a major problem in homes in the US, with growths found in more than 70 percent and 45million houses have unhealthy levels of mold, as well as schools — with 30 percent having roof problems that could lead to mold in buildings.
While the fungus can pose a health risk anywhere it is found, experts warned it was particularly concerning if it is found in an air conditioning unit because this can blow mold spores into the air, allowing them to spread further.
The above shows six types of mold you’re most likely to find in your home
Dr Money said: ‘You have these highly-publicized cases, particularly in the UK, where children have suffered and some have died from mold exposure.’
If mold is discovered in your home, Dr Money recommended using bleach or dish detergent to scrub the surface clean or throw out items covered in the substance.
It is also important, he added, to wear a face mask during the process to avoid breathing in spores.
More than 75,000 people are hospitalized with fungal infections in the US every year, and at least 7,000 die from them, though it is not known how many of these instances are linked to mold in the home.
Below DailyMail.com lists what each color of mold means:
Black mold
Black mold, or toxic mold, colonizes multiple surfaces that have been wet for an extended period of time, including walls, AC units and bathrooms.
While color is not particularly important for determining the health risk mold poses, Dr Money said some consider this to be one of the riskier types.
‘Certainly, if it was my home, I would be concerned if I got a pizza box-sized area of dusty blackness,’ he said.
Black mold, or toxic mold, is one of the most risky in homes because it can release spores and toxins, experts say. It is particularly concerning if it spreads to cover an area larger than a pizza box, as shown above
The mold — called ‘Stachybotrys’ — is sticky, making it difficult to spread its spores in the air, limiting the risk.
But Dr Money warned that if it covered a large area in a home, it would release a lot of spores that could cause complications for babies and children, whose developing lungs are particularly vulnerable.
In January last year, the mold was blamed for the death of two-year-old Awaab Ishak in the UK, who suffered ‘severe swelling’ in his airways and throat.
Some slimy black mold found in areas like showers, however, may be a different type called Aureobasidium.
This yeast-like fungus can also cause respiratory allergies, but is very unlikely to threaten human life.
Bleaching or dish detergent can kill off both types of black mold, although in some cases the dark pigmentation may remain on the wall for some time.
Blue and green mold
These molds are among the most common to infest homes.
Blue mold is the fungus Penicillium, which led to the discovery of the powerful antibiotic Penicillin, and is commonly seen on cheeses, but can also infest walls, ceilings and other foods.
It is safe to eat in cheese, experts say, because the acidity, salinity and temperature of the cheese prevents it from releasing toxins.
But it should still be removed from homes and other foods should be discarded, experts say.
Dr Money also said that blue (left) and green (right) molds were concerning if they spread to cover an area larger than a pizza box. They are particularly common in homes
Green mold is a type of mycelium fungus, and often colonizes items in the fridge that have been left uneaten for too long, as well as carpets.
Dr Money again emphasized that the color of the mold was not important, but said that this mould could also grow to cover a large area — raising health concerns.
Experts have also warned that spores released by green mold can remain in the air for months.
If the lungs are regularly exposed to a lot of mold spores, this can trigger the immune system to over-react — causing asthma, coughing, and chest tightness.
Pink mold
Everyone has likely seen pink moldy areas in their bathrooms, collecting around faucets, drains or on shower curtains.
This is known as Serratia, experts say, which is actually a bacteria that grows in damp areas and feeds off residue from soaps and shampoos.
Many of us may also have pink mold in our bathrooms, which experts say can also pose a risk
Experts say in most cases it is harmless, and can easily be wiped away using a sponge and some dish detergent.
But if there are large quantities in a bathroom, the bacteria can become airborne and then be breathed in — risking health complications.
The bacteria can cause infections in the urinary and respiratory tract, as well as wound and eye infections in some cases, experts say.
People who have compromised immune systems or underlying conditions are more at risk from the pink growth, but it can be removed using bleach or dish detergent.
Yellow and orange mold
Stemphylium and Epicoccum are two yellow and orange molds found in the home.
They can colonize damp paper, cardboard, and flooring — as well as houseplants and carpets.
Unlike most molds, these need sunlight to complete their life cycle — so they are unlikely to be found in dark places.
In some cases, walls can be infested with yellow mold
But they can fill the air with spores when large colonies emerge, potentially raising the risk of someone suffering from an asthma attack.
However, using soap and warm water or bleach will likely rid any infested areas from the growths.
White mold
While there are numerous types of white mold, Cladosporium is one of the most common types to crop up inside.
Like Aspergillus, this type can be airborne and is typically found in moist and dark areas such as basements, bathrooms or attics.
According to Healthline, it can also grow on carpets, vents and even paper, provided the conditions are right.
Most forms of Cladosporium are not dangerous to humans, but the fungi can still worsen asthma and allergies.
And white mold, pictured above, can also emerge and infest some homes
This coral-looking species is a parasite of moths and cicadas that has often been used in pest control products.
Michael Taylor, a mold expert from Flinders University in Australia, previously told DailyMail.com: ‘So when you notice the world around you changing color, you can marvel with your newfound knowledge at the microscopic wonders that live complex lives alongside yours.
‘Then maybe clean it up, and give the fruit bowl a wash.’