High levels of diarrhoea-causing bacteria in popular street foods including chotpoti: Study

Infographics: TBS

A recent study by the Bangladesh Food Safety Authority (BFSA) has revealed alarming levels of harmful bacteria in popular street foods sold in Dhaka.

The study found that items such as chholamuri, chatpati, sugarcane juice, aloe vera sherbet, mixed salad, and sandwiches contained high levels of diarrhoea-causing bacteria, including E coli and Salmonella.

The findings were presented at a ceremony held at the BFSA office in Dhaka on Sunday (9 June), chaired by BFSA Chairman Zakaria.

The study, titled "Prevalence of Microbial Hazards in Street Food and Ready-to-Eat Salad Items in Restaurants and Their Probable Risk Analysis," was led by Md Latiful Bari, chief scientist and head of the Food, Nutrition and Agriculture Research Laboratory at the Centre for Advanced Research in Sciences, University of Dhaka.

Testing 450 samples from 50 locations across Dhaka North and South City, the study found all samples to be contaminated. The primary culprits were E coli, Salmonella, and Vibrio.

According to Bari, "These bacteria are not supposed to be present in any food. However, they have been found in high concentrations in popular street foods. The main reason for this is the lack of safe water sources, which allows harmful bacteria to enter the food."

In addition to contaminated water, the study identified poor hygiene practices, such as unclean towels and unwashed hands, as significant contributors to food contamination.

Vendors' lack of knowledge about hygiene and food safety worsens the problem, with contaminated utensils and surfaces spreading bacteria further.

Despite claims in the finance minister's budget speech for the fiscal year 2024-25 that 98.8% of the population has access to safe drinking water, the reality appears starkly different.

Bari expressed concern over the inaction regarding food contamination. "The situation is getting so bad that it seems like nothing will be done unless there is a massive crisis like the Covid-19 pandemic," he said. "But it is urgent to take action on this issue."

Researchers said that ensuring safe drinking water is critical to addressing food safety. Dhaka's water supply, managed by the Dhaka Water Supply and Sewerage Authority (WASA), is reportedly so poor in quality that it is undrinkable. Without improving water quality, food contamination will persist.

The event's chief guest, AHM Shafiquzzaman, director general of the Directorate of National Consumers' Right Protection, highlighted the broader issue of environmental pollution contributing to food contamination.

"Heavy metals are being found in rice," he said. "This is because our water, soil, and air are all polluted. The problem starts at the source of what we produce, and street food vendors often lack basic knowledge of hygiene."

Shafiquzzaman stressed the need to tackle street food contamination and water quality issues. "We are working to build a smart Bangladesh," he said, "but that requires a healthy population. If we can't solve these problems, we will become a crippled nation."

The issue of contaminated WASA water is longstanding. Previous studies have found E coli, textile chemicals, and other harmful substances in WASA water.

A recent study by the Environment and Social Development Organisation (ESDO) and the International Pollutants Elimination Network (IPEN) found per- and polyfluoroalkyl substances (PFAS) chemicals in WASA water, which are linked to cancer.

In 2021, another ESDO study found industrial chemicals perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in WASA water, also associated with cancer and other health problems.

Banana ripening issue

At the same event, Professor Abul Hasnat M Solaiman from Sher-e Bangla Agricultural University presented a study on the proper banana ripening process.

The research revealed that wholesale banana sellers use various chemicals, including banned ones like calcium carbide, despite claiming they use heat chambers for ripening. There is no safe way to apply these chemicals directly to the bananas.

Professor Solaiman explained, "Ethylene is a globally recognised ripening agent, but its import is banned in Bangladesh. There are also no scientific chambers for ripening bananas and other fruits, leading to the use of harmful chemicals. Allowing the import of ethylene would solve this issue."

The researchers developed a sample ripening chamber costing Tk4 lakh, which eliminates the need for harmful chemicals. If produced commercially, the cost would decrease, and each chamber could last up to 10 years.

Shafiquzzaman suggested that the city corporations promote the use of these chambers and consider signing an MoU if necessary.

Additionally, a representative from the Ministry of Commerce said that they would recommend including ethylene in the import list for the next fiscal year.