Real, living threat of cadmium in rice
“Itai! Itai!” This is Japanese for “it hurts! It hurts!” It is also the name of a disease that emerged in the early 20th century in the Toyama area (prefecture) of Japan, due to cadmium poisoning, .
Itai-itai disease was the name locals gave to severe spinal and joint pains. Though locals didn’t know it at the time, cadmium poisoning can cause softening of the bones and kidney failure. It came about due to two neighbouring, interconnected practices: Mining and rice irrigation.
Cadmium released into mountain rivers by mining companies settled on the river bed, along with other heavy metals. So when river water was used to irrigate the paddy fields, the soil, and the people were poisoned.
In a classic case of the dictum “don’t learn late lessons from early warnings”, the problem emerged as early as 1912 , while the compensation payouts only began as late as the 1970s.
From the 1980s to 2012, a massive soil replacement programme cleaned polluted rice paddy fields. As a result, the cadmium content in rice has “markedly decreased”, according to Keiko Aoshima, director of the Hagino hospital and published author on the topic.
His 2016 article in the peer-reviewed journal Soil Science and Plant Nutrition states: “Cd nephropathy [kidney disease caused by cadmium] is still prevalent, progressive and irreversible among the inhabitants of the Jinzu River basin, and new occurrences of itai-itai disease are found even today.”
This may seem as relevant as the start of many a fairy tale — “long, long ago and far, far way” — to those of us on this island floating off the north west of Europe.
However the EU has been trying, unsuccessfully, to reduce cadmium exposure in its citizens for years.
The source of cadmium contamination of European soil? Mineral fertilisers.
A December 2016 European Parliament report says: “The long-term use of mineral phosphorus fertiliser has contributed to increased cadmium concentrations in agricultural soils. There are indications that crops produced by organic farming, specifically cereal crops, have relatively low cadmium concentrations, though this is not certain.
“This is highly relevant to human health as food is the dominant route of human exposure to cadmium in non-smokers. The population’s current cadmium exposure is close to, and in some cases above, tolerable limits. There have been no studies comparing the effects of long-term organic versus conventional farm management on cadmium concentration in crops.
“However, long-term experiments over more than 100 years indicate that cereal crops fertilised with mineral fertiliser tend to have higher cadmium content compared to cereal crops fertilised with animal manure. This issue is highly relevant to human health and deserves further investigation.”
Meta-analysis by Baranski et al, with 343 original peer-reviewed studies published between 1977 and December 2011, revealed a 48% higher cadmium content in conventional crops. “Fertilisation strategies developed and used in organic agriculture, and limits for the cadmium content in mineral fertilisers, constitute potential strategies for decreasing the cadmium concentration in conventionally-produced crops.”
However, as is typical, the human health impact is not paid for anywhere in the conventional food chain. Organic crops, with lower yields and, arguably, lower cadmium levels, cost more per tonne to produce and for the consumer in the form of foodstuffs.
The public health purse takes up the slack, so the tax payer pays. The organic consumer self-taxes by buying the more expensive product — thus paying twice.
And yet, in the strange word of EU bodies and its reporting, another recent document somehow states “the expected additional costs of introducing mandatory or voluntary maximum threshold levels for cadmium in inorganic fertiliser are larger than the expected benefits”.
It seems unlikely, to this columnist anyway, that 21st-century Europeans have a higher pain threshold than early 20th-century Japanese.
