Sulphur concerns: Why it is harmful to humans

Importation of low-quality fuel into the country is likely to result in increased hospitalisation and health complications because of high sulphur content, health experts have warned.

Petrol and diesel being imported contain up to 50mg/kg of sulphur, against the previously adopted standard of below 10mg/kg.

According to health experts, the higher sulphur content poses a major public health concern and is likely to trigger more respiratory-related illnesses.

Joseph Wahome, a consultant toxicologist, warned that the move could significantly increase sulphur emissions into the atmosphere, raising public exposure levels fivefold.

In an exclusive interview with The Standard, Dr Wahome explained that sulfur naturally occurs in crude oil as part of the extraction process.

However, when fuel is burned in vehicle engines, sulphur is released as sulfur dioxide, a harmful gas that affects the human respiratory system.

Respiratory system is affected because of inhalation of the fume that causes irritation on the nose, lungs, throat, leading to coughing, wheezing, and breathing difficulties

Respiratory system can further cause chronic bronchitis, (tubes that carry air to and from the lungs), an inflammation of the airways.

“Once fuel fumes are inhaled, people may experience shortness of breath, while those living with asthma are likely to experience more frequent attacks,” warned the specialist.

Wahome added that sulfur exposure can also irritate the eyes, while individuals who are allergic or hypersensitive to sulfur may develop skin reactions such as itching and irritation.

Individuals with with hypersensitivity to sulphur may also experience itching and flare-ups over time.

“Individuals who are sensitive to sulphur can develop eye and skin reactions, including itching and irritation,” he noted.

Children are more vulnerable to sulphur because their respiratory and immune systems are not yet fully developed.

“Children are more affected because their natural body defence mechanisms are weaker than those of adults, making them more susceptible to the harmful effects of sulfur exposure,” said Wahome.

Sulfur, he noted is caustic in nature, and once inhaled into the lungs, it mixes with fluid and irritates the tissues (lining of the respiratory tract system).

Naturally, the body has defence mechanisms, but in this case, if in contact with sulfur, the body that triggers a reaction, leading to inflammation.

“When the body reacts to protect itself, the inflammatory process begins, which can lead to bronchitis. For individuals already predisposed to asthma, sulfur exposure can trigger asthma attacks,” he explained.

As sulfur is inhaled, he said it enters the respiratory system and settles along the lining of the lungs and bronchial tubes, where it causes irritation.

The body then responds to protect itself, but because the exposure is continuous, it results in ongoing inflammation.

“Sulfur irritates the lining of the respiratory tract when inhaled. As the body continuously reacts to protect itself from this irritation, it triggers an inflammatory process, which can lead to bronchitis and worsen asthma symptoms in people who are already vulnerable,” added Dr Wahome.

Further, he explained that once sulphur is released into the air, it reacts with water vapor to form acidic compounds, leading to the production of sulfuric acid and acid rain.

This atmospheric contamination can then cause corrosion of buildings, infrastructure, and other materials.

Limiting sulphur content in fuel according to Wahome is not only a Kenyan concern, but global.

Globally, there has been a push to reduce sulfur in fuel.

In Kenya, congestion on highways, and individuals living in urban settings raises a health concern.

“Because of high content of sulphur in fuel in Kenya, you start seeing people with more cases of asthma attacks in hospitals, you start seeing people developing bronchitis in higher numbers.

If this happens, we may end up seeing hospital visits becoming a concerns with respiratory attacks and infections. It is generally a concern, actually for health authorities,” observed Dr Wahome.

 Public health Union National General Secretary and CEO Brown Ashira said strict regulations need to be enforced in importation of fuel to the county.

“Continued importation of fuel with high sulphur results to increased sulphurdioxed emissions contribute to air pollution and acid rain, leading to potential health issues like bronchitis,” he said in an interview.

Sulphur, Wahome noted naturally occurs in the environment, but the concern with waived fuel is the level of concentration.

For instance in congested areas or when people are stuck in traffic with multiple vehicles idling, sulfur is emitted as sulfur dioxide during combustion in engines, increasing exposure.

“The issue is concentration. If you are sitting in traffic and all vehicles have their engines running, you are continuously breathing in air containing sulfur emissions,” said Wahome.

He warned that increasing sulfur levels in fuel from 10 milligrams per kilogram to 50 milligrams per kilogram means exposure could rise fivefold.

“Previously, we were dealing with 10mg per kilogram, but now at 50mg, this is five times more sulfur. If you are seated in the same traffic, breathing the same air, your exposure is significantly higher. This is the challenge we are likely to face,” he said.

According to him, avoiding exposure may be difficult as long as higher-sulphur fuel remains in circulation.

People may have little choice but to use protective measures or avoid heavily congested areas in towns and cities.

“As long as fuel with higher sulphur concentration is being imported, exposure may be unavoidable. The government should issue public health advisories,” he said.

He noted that while Kenya had previously agreed to maintain sulfur levels below 10 parts per million (ppm), some East African countries, including Uganda and Tanzania, allow up to 50 ppm, partly because fuel with higher sulfur content is cheaper.

“The higher the sulfur content, the less refining is required, which lowers fuel prices. Highly refined fuel with lower sulfur is more expensive,” he explained.

He urged the government to shorten the six-month transition period and issue public health alerts to help Kenyans reduce exposure.

“The government should work towards reducing this period as much as possible and provide public health guidance on how people can mitigate exposure,” he said, citing need for a broader national conversation to focus on toxic substances in the environment and strategies to minimise public exposure.

Wearing of facemask, according to the expert is a mitigation to avoid inhaling highly concentrated sulphur as witnessed during Covid-19 pandemic.

The government and policy makers should also prepare to handle more causes of respiratory infections and diseases.

This includes equipping hospitals with diagnostic tools and medicine.

“The public might be forced to wear facemasks all the time while on the road.

In the coming days, Kenya is likely to report increased number of patients, and hospital visits. We have to be on the look-out,” warned the expert.

Ashira added that the Government should set up more food and water quality laboratories to test heavy metals and conduct and food and water quality surveillance.
Further, he said there is need to employ and recruit public health specialists on food to provide continued health education and surveillance.