Study finds contaminated fruits, vegetables in Arusha

Arusha. As the demand for sustainable food systems increases globally, a recent study reveals the production, trading and consumption of fruits and vegetables in Arusha City that are highly contaminated with pesticide residues.

The findings of the study conducted between 2019 and 2021 were presented in Arusha by Tanzania Plant Health and Pesticides Authority (TPHPA) researcher, Dr Jonas Kapeleka, during a day-long capacity-building training on sustainable food systems for media owners and editors.

The training was co-organised by the network of farmers and livestock keepers, Mtandao wa Vikundi vya Wakulima na Wafugaji Mkoa wa Arusha (MVIWAARUSHA), the Global Alliance for Improved Nutrition (GAIN), Iles de Paix (IDP) and the Agriculture Non-State Actors Forum (Ansaf).

Titled Assessment of the Food Safety Risks Along the Main Fruit and Vegetable Supply Chains in Arusha City, the study that was carried out in Arusha City aimed at establishing the safety levels of fruits and vegetables.

The fruits and vegetables involved in the study include tomatoes, onions, black nightshade, curly kale, cabbage, carrot, okra, spinach, tomatoes and watermelon among others.

Presenting the findings, Dr Kapeleka said the study aimed at establishing levels of contamination: biological, chemical and physical in Arusha, Kilimanjaro and Manyara regions.

“Fruit and vegetable traders, transporters as well as storage value chain stakeholders were involved, with  Kilombero, Tengeru, Mto wa Mbu, Samunge, and Ngaramtoni among markets earmarked during the study,” he said.

The findings show that 63 percent of sampled fruits and vegetables had been contaminated by at least one microbial contaminant.

This, according to Dr Kapeleka, means that 63 percent of fruits and vegetables produced and consumed in Arusha are contaminated with bacteria, noting that samples gathered from marketplaces have higher contamination levels compared to those collected from the farms.

“This is attributed to customers’ behaviour, which involves touching vegetables before purchasing. The same happens to fruits too,” said Dr Kapeleka.

Furthermore, he said over 90 percent of the analysed bacteria are pathogenic (disease-causative) micro-organisms, insisting that spinach, watermelon, onion, tomatoes, carrots, and curly kale were among the crops found to be contaminated with pathogenic bacteria, with some containing up to five different bacteria.

He said fruits and vegetables collected from marketplaces had higher levels of pathogenic bacteria as compared to samples collected from farms primarily due to poor hygiene in most markets.

“Market environments are excessively dirty, with some products being arranged on the ground. People should avoid purchasing vegetables piled on the ground despite being cheap,” he suggested.

According to him, some of the products are arranged on the ground close to dumps, where garbage collection systems have completely collapsed despite traders having paid pre-requisite levies.

Furthermore, Dr Kapeleka said some of the markets have their sewerage systems blocked and that several others lack storage facilities.

“During the study, water and pieces of clothing that are used for watering and cleaning the vegetables were also tested and found to contain enough bacterial contamination,” he said.

He said farmers don’t bother about the originality of the water used for watering the vegetables, noting that unsafe and unclean water increases contamination levels.

Regarding the presence of chemical contamination or pesticide residues, Dr Kapeleka said analysis of fruits and vegetables established that 47.5 percent of collected samples contained pesticide residues, with those collected from marketplaces surpassing those from farms.

“Farmers have been harvesting crops with pesticide residues, they are taken to the market with the chemicals where consumers buy and consume them,” he said.

“Farmers don’t follow the allocated harvest timetable to give pesticides enough exposure to sunlight and therefore reduce their poisonous nature,” he added.

He said samples collected at highway selling points such as Himo were found to be highly contaminated with pesticide residues due to excessive spraying applied to protect the fruits from pests.

He said some farmers and traders have been carrying out secondary spraying after harvests and during packaging to prevent pests’ transmission from other products in the market.

But, the World Health Organisation (WHO) has provided the pesticide residue tolerance level for fruits and vegetables globally, according to him.

“However, when compared to the WHO pesticide residue tolerance, 75 percent of the locally produced fruits and vegetables were found to surpass the WHO permissible threshold,” he said, noting that samples from the highways contained over 90 percent pesticide residue.

He added: “Generally, fruits and vegetables that are produced and consumed in Arusha are highly contaminated with both bacterial contaminants (pathogenic bacteria) and pesticide residues.”

He said bacteria contaminants lead to several diseases such as diarrhea, Urinary Tract Infection (UTI), Respiratory Tract Infection (RTI), and several others.

But, excessive pesticide residue causes complications in the nervous system and problems in the reproductive systems through the destruction of the hormonal systems of both males and females.

“The chemicals destroy the sperms’ deoxyribonucleic acid (DNA) whereby both the head and tails are adversely affected leading to individuals’ failure to reproduce,” he said.

“This leads to miscarriages in affected women and mental complications in children. Women are mostly affected due to their physical nature. Therefore, they should avoid drinking milk after working in the farms that have just been sprayed with pesticides,” he added.

According to Dr Kapeleka, men are less affected because they spend less time in fruit and vegetable farms than women, who are also more vulnerable due to higher fat deposits in their bodies.

However, he stated that farmers would be unable to stop using pesticides on their farms and switch to 100 percent organic farming production.

But he said an emphasis on the accurate and safe use of pesticides will pave the way for a reduction in use that will later be followed by the complete abandonment of utilisation.

“Pests attacking crops are usually controlled by friendly pests, therefore leaving the crops with low levels of damage or completely unaffected. But, the ongoing excessive use of pesticides kills friendly pests, therefore doing away with control mechanisms,” he said.

As a result of the lack of enemies, destructive pests overproduce, similar to how lions serve to control the population of gazelles in the ecosystem.

Speaking on the roles and opportunities of the media in supporting food systems transformation, the MVIWAARUSHA coordinator, Richard Masandika said practitioners are supposed to understand several issues.

They include issues of Sustainable Food Systems (SFS), awareness of the creation, advocating SFS and integrating the organisation’s strategies.

“They should also train journalists in the context and realities of SFS and disseminate accurate SFS information to the public. Areas of focus should include making simple analyses of policies, strategies, and plans related to agroecology in the country,” he said.

Masandika said the media should also explore opportunities and address gaps for agro-ecological transformation, create awareness about why it is important to streamline agro-ecology in national policies, plans, and explore expected potentials,” he said.

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