Could Kenyans still, unknowingly, be eating tainted fish from China?

The fish you consume at restaurants in urban areas is disguised as local catch amid rising consumer concerns over imports from China and helplessness by the standards agency to enforce safety.

At the Gikomba market in Nairobi, Chinese fish is sold openly after being repackaged by traders in baskets. This involves removing the frozen pieces from the packed boxes, which come with a two-year expiry date, repacking and sending them to various locations by handcarts. Should anyone ask the source the instructions are firm: from Lake Victoria.

Laboratory tests commissioned by the Nation two weeks ago revealed that fish imported from China had traces of mercury, lead, arsenic and copper exposing millions to health risks.

The Kenya Bureau of Standards (Kebs), however, denies the fish poses any danger to human health.

AFFORDABILITY

In a response to queries by the Nation over the health concerns raised by the laboratory results, Kebs said that tests on fish samples from various sources at its accredited laboratories had not found any lead, copper and mercury.

“All imports to Kenya are required to be tested at the country of origin and, if they meet the specifications in the standards, they are issued with a certificate of conformity. Upon arrival in Kenya, the imports are subjected to destination inspection,” the agency said.

Fish imports are not subjected to further laboratory tests once they land in the country. Kenya has therefore left consumers at the fate of Chinese approved agents.

The Chinese fish is preferred by traders for its affordability with a box containing almost 60 pieces going for Sh2,700 in wholesale rates. This compares to Sh450 apiece for fish from Lake Victoria.

The commodity has become more popular in restaurants, open markets, kiosks, roadside eateries and the famous Gikomba market in Nairobi because of its affordable costs even as the locally farmed product struggles to meet the growing demand.

Despite being within the permissible limits according to the United Nations standards, the presence of heavy metals such as lead, mercury, copper and arsenic in the human body poses serious health risks after long-term exposure, raising concerns on the increasing rate of consumption of the contaminated fish.

PERMISSIBLE STANDARDS

The Nation took samples of fish imported from China and purchased from vendors at Gikomba to the University of Nairobi’s Public Health, Pharmacology and Toxicology laboratory and found traces of lead, copper, mercury and arsenic.

The results confirmed residues of 0.04 ppm of lead, 0.005 ppm of mercury, > 0.001 ppm of arsenic and 1.2 ppm of copper, indicating possible contamination of the water ponds used to farm fish that is later imported into the region.

“The results shows that these fish have permissible standards limits, but it is still worrying that their presence can still be detected in them. Long-term exposure to these metals through frequent consumption can have a disastrous effect to the human body and poses serious health risks,” Professor James Mbaria, head of UoN’s public health department, said of the results.

The presence of the heavy metals in the imported fish means that these farmed products are exposed to either use of petrol powered water pump or pesticide application apparatus leading to contamination of their ponds and exposure to lead and copper.

For consumers, this will be of definite concerns given that the possibility of harmful effects cannot be ruled out after a long period of consumption of these fish.

“Heavy metals can cause serious health hazards and any potential dietary exposure to lead or mercury possess possible risk to human health,” Professor Mbaria said.

The Nation undertook the study following health fears over the Chinese export after several countries, including the United States, called for stricter enforcement of safety and health checks by Chinese authorities on the food commodity.

The laboratory tests were intended to determine the level of drug residues including streptomycin, sulfadimidine, oxytetracycline, and penicillin, as well as pesticide residues.

HEAVY METALS

The heavy metals tested included lead, copper, mercury, arsenic and copper. The test results did not detect any drug or pesticide residue in the samples.

Kenya has recently turned to China to meet its fish consumption demand, which has seen its fish imports from the Asian nation double over the last two years to hit highs of $20.1 million in 2017 from $10.2 million the previous year, adding impetus to concerns that the Asian nation is flooding the market to the detriment of local fishermen.

According to the Kenya National Bureau of Statistics (KNBS), Kenya spent $22.17 million on fish imports in the first 11 months of 2017, reflecting the strong hold China has over the local fish market, as it accounted for more than 90 per cent of these imports.

The Chinese imports, which stood at $6.24 million in 2015, comes at a time when local production was falling amid dwindling stocks in the lakes.

Frozen fish that included tilapia and mackerel was the most imported fish stock from China, with more than 19,000 tonnes worth more than $18 million. This category included mostly frozen and chilled tilapia.

The presence of toxic metals is not just limited to the imported fish. Several recent studies of Kenyan farmed fish also revealed that there exist potential hazardous chemicals in the products exposing consumers.

Two years ago, a study by the University of Nairobi led by Dr Isaac Omwenga tested 213 fish samples from 60 ponds in Kiambu and Machakos and found them to be contaminated with banned agricultural chemicals, with some having the potential to cause cancer.

TOXIC ELEMENTS

Human poisoning from aldrin and dieldrin is characterised by major body convulsions. Heptachlor is highly toxic to humans and can be absorbed through the skin, lungs and the food tract.

These chemicals are banned in most countries and in Kenya by the Pest Control Products Board. The study showed lindane and DDT as the most prevalent in all the samples analysed.

“While the contamination did not breach international health safety standards, it is an extremely worrying trend,” Dr Laetitia W. Kanja of the University of Nairobi and one of the study authors said.

Soil sediments

The UoN's public health department had in June 2013 tested for lead and copper in fish and soil sediments in farmed fish within Kirinyaga and found high levels of lead, which they said could have been as a result of the agricultural methods of fish farming practised in the area.

“Heavy metals that may be found in fish include mercury, cadmium, arsenic, chromium, thallium, and lead which have a tendency to bio accumulate in the food chain and can be highly toxic to human even at low concentrations.”

“These toxic elements are transferred to human through consumption of contaminated fish resulting to a negative effect on human health.”

“On absorption, pollutants are transported in the blood stream to either the bone or liver for transformation and storage,” the researchers said in their report published in the Journal of Applied Science and Environmental Sanitation.