The fish you consume at restaurants in urban areas is disguised as a 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 but after being repackaged by traders.
This involves removing the frozen pieces from the packed boxes that come with a two-year expiry date.
After repacking, they are sent to various locations by handcarts. Should anyone ask the source of the fish, 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.
In a response to the Nation on the health concerns raised by the laboratory results, Kebs said tests on fish samples from various sources at its accredited laboratories did not find any lead, copper or 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 fish consumers at the fate of Chinese-approved agents.
The Chinese fish is preferred by traders because it is affordable, with a box of about 60 pieces retailing at Sh2,700 among wholesale traders. A piece of medium-sized fish from Lake Victoria costs Sh450.
The Chinese fish has become more popular in restaurants, open markets, kiosks, roadside eateries and the famous Gikomba Market in Nairobi even as the locally farmed product struggles to meet the growing demand.
Though the levels of contamination with heavy metals such as lead, mercury, copper and arsenic are within the United Nations’ maximum permissible standards limits, their presence and long-term effects in the human body pose serious health risks.
The EastAfrican (a publication of Nation Media Group), took a sample of Chinese imported fish, which it purchased from vendors at Gikomba, to the University of Nairobi’s Public Health and Pharmacology laboratory and traces of lead, copper, mercury and arsenic were found in the fish.
The results confirmed residues of 0.04 ppm of lead, o. 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 these fish, which are later imported into the region.
“The results show that these fish have permissible standard limits, but it is still worrying that their presence can be detected. Long-term exposure to these metals for the human body, through frequent consumption of such food, can have a disastrous effect,” Prof James Mbaria, the University of Nairobi’s Public Health head of 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 hence the exposure of lead and copper.
For consumers, this will be of definite concern given that the possibility of harmful effects cannot be ruled out after a long period of consumption of the fish.
“Heavy metals can cause serious health hazards, and any potential dietary exposure to lead or mercury possess possible risk to human health,” Prof Mbaria said.
The EastAfrican undertook the study following previous health fears on fish imported from China after several countries, including the US, called for stricter enforcement of safety and health checks by Chinese authorities on the commodity.
The Nation laboratory tests were intended to determine the level of drug residues including streptomycin, sulfadimidine, oxytetracycline, and penicillin, as well as pesticide residues.
The test results did not detect any drug or pesticide residue in the Chinese fish sampled.
Kenya has recently turned to China to meet its fish consumption demand, which has seen its fish imports from the Asian nation double in the past two years to hit $20.1 million (Sh2 billion) in 2017 from $10.2 million the previous year, adding impetus to concerns that China is flooding the local market with fish 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 strangle for the Chinese fish market locally, as it accounted for more than 90 percent of these imports.
The Chinese imports, which stood at $6.24 million in 2015, came at a time when local production was falling over concerns about dwindling stocks.
Pollution of fish-breeding areas, slow uptake of new production methods like cage farming and fish ponds as well as lack of standard inputs like fingerlings and feeds mean that Kenya will continue importing fish into the foreseeable future.
However, renewed national attention on the blue economy could see the country become self-sufficient in fish production, leaving some for export in the long term.
Frozen fish that included tilapia and mackerel was the most imported fish stock from China.
Tanzania, which controls more than half of Lake Victoria, also saw a 23 percent increase in its fish imports from the Asian nation, to stand at $8 million as at the end of last year, having doubled from $3.6 million in 2014.
Dar es Salaam imported frozen Pacific mackerel, Indian mackerel, chub, frozen sardine and Una tilapia.
Tilapia had the highest value per tonne at $2,300 followed by the Pacific mackerel at $1,002 per tonne. In 2017, it imported more than 12, 000 tonnes of the mackerel fish species.
The presence of toxic metals is not just limited to the imported fish given that several recent studies of Kenyan farmed fish also revealed that there exist potential hazardous chemicals in the products.
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.
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.
“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.