Lack of hygiene in a car promotes bacteria build-up, particularly if food is not cleaned out, health experts say. Image Credit: Ahmed Kutty/Gulf News

Dubai: Are car interiors a breeding ground for micro-organisms and bacteria including E.coli? Research by microbiologists in the UK suggests this is so.

According to the studies, between 283 and 700 bacteria count per sq cm were found in an average car. In terms of comparison, a public toilet is said to have an average of 500 bacteria per sq cm count.

Cars that had children and pets as passengers and those that usually had food and drink spillage harboured more bugs and bacteria, the study revealed.

So, if you are in the habit of regularly eating and drinking in your car, stowing away rubbish in the foot wells and not cleaning it out daily, how bad can it be for your health?

Dr Mazen Naba, a specialist in infectious diseases and internal medicine and chairperson of infection control at Medcare Hospital said bacteria live everywhere in the environment whether it is inside a car or on other surfaces, but in the case of bacteria that cause sickness, their ability to trigger infections comes down to specific characteristics.

“Bacteria must contain pathogenic factors to be able to cause infections,” said Dr Naba. “Exposure to few bacteria either through contact, ingestion or inhalation is not enough to cause an infection. There must be exposure to a large amount of pathogenic bacteria or a loss of natural immunity for a person to get an illness,” he said.

Theoretically, he said, bacteria such as E coli and Bacillus Cereus can cause certain infections like blood stream and skin and soft tissue infections and food poisoning, but only if these bacteria are pathogenic and contracted in specific settings.

“Most community bacteria lack the pathogenic factors that cause infections, but skin and soft tissue infections caused by E. coli were not uncommon in outpatient department clinics,” he said.

But Dr Naba’s expertise also leads him to believe that E. coli and other related bacteria cannot survive on car surfaces because of the effect of sunlight and high temperatures, therefore, ingestion of dangerous and large volumes of bacteria in the car is not possible. “Most of the time, our natural immunity is strong enough to resist exposure to environmental bacteria,” he said.

Even though these types of infections are reported, it cannot be confirmed if the source of the infection comes from the confines of a car or from somewhere else, he added.

However, we must take precautions to protect ourselves from these bacteria, such as washing hands before eating and maintaining hygienic car interiors, Dr Naba said.

Dr Mohammad Rafique, head of pulmonology and sleep medicine at Prime Hospital said that though it is rare to catch infections from bacteria found in cars, there is a possibility that unhygienic cars and poorly serviced car AC and filters — which accumulate bacteria, moulds, dust and allergens — can cause respiratory allergies.

“Inhaling allergens, especially dust and dust mites in cars, can cause respiratory allergies, rhinitis and cough and can aggravate breathing problems in people who suffer from asthma and allergic rhinitis, especially in long-term exposures,” he said.

Some of his patients, he confirmed, suffer from respiratory symptoms the moment they switch on their car’s air-conditioning and feel better only when they move out of that environment.

“Replacing car cabin filters and checking and cleaning AC ports is extremely important,” said Dr Rafique. “It improves indoor breathing air quality and causes fewer triggers for people with respiratory problems. It also prevents respiratory ailments, like a simple flu.”

Lack of hygiene inside a car, the doctors said, plays a big role in promoting the growth of bacteria. For example, food debris is a favourable environment for bacterial growth. Also, Bacillus cereus strain of bacteria can be brought in with soil residue on shoes or from pets’ feet, they said.

Both doctors recommended regular car washes to prevent accumulation of debris and growth of bacteria inside a car.

Rizwan Rehmad Ali, a mechanic at Salim Ali Bin Haidar Garage in Dubai, advised people to invest in regular maintenance of car interiors.

“[Car] interiors must be refreshed twice a month to get rid of dust or food spills,” said Ali. “There are many areas that accumulate germs like the steering wheel, gear knob, seats, arm rest and floor mats. But the most dangerous is a ill-maintained cabin air filter.”

This must be replaced every six months, said Ali, because it catches dust, pollen and other airborne material that can lead to allergies and bad odour. “You see many people sneezing all the time [inside a car] because their cabin air filters are dirty and have not been changed for a long time. The cabin air filter cleans the air that comes into the car interior, the heating, ventilation and AC system.”

Driving in heavy traffic and in dusty climates and experiencing persistent bad odours in car interiors is a sign that cabin air filters need to be replaced, said Ali.

Car cleaning check-list

Ensure your car is not only washed from the outside but also thoroughly wiped and vacuumed from the inside.

Make sure the dashboard and cup holders are wiped clean, and seats, floor mats and foot wells vacuumed.

Food leftovers and cigarette ash should be cleared on a daily basis and not allowed to wait till the next car wash.

Cars with fabric upholstery harbour more germs as compared to leather, which can be wiped away easily with a mild detergent solution.

Since fabric can stain and attract dirt easily, an annual deep cleaning for car interiors is a must.

Keep a hand sanitiser inside the glove compartment and use it before touching the steering wheel, if your hands are not clean.

Educate children about keeping the car clean and not spilling food and drinks inside the car.

Refrain from smoking in the car.