Risk in Brief - Cadmium in Food

Cadmium in Food

Introduction

  1. Cadmium is a metallic element that occurs naturally in the Earth's crust. It can also be released to the environment by human activities. Cadmium has a number of industrial applications such as electroplating, pigment production, manufacture of plastic stabilisers and pigments, nickel-cadmium batteries and electronics, etc. Fertilisers produced from phosphate ores, industrial operations such as mining, mining refining are important sources of environmental contamination.
  2. For non-smokers, food is the main source of cadmium intake for the general population. Plants, animals, fish and shellfish will take up cadmium when grown in contaminated environment (soil, air, water, fertilizers, feeding stuffs, etc). However for smokers, tobacco smoke is an important source of exposure to cadmium.

Toxicity of Cadmium

  1. Animal studies show that an acute intoxication of cadmium may cause damage to the gastrointestinal tract as well as affecting functions of the liver, heart and kidney. However, acute toxicity of cadmium due to dietary exposure is very unlikely.
  2. With chronic toxicity to cadmium, the kidney appears to be the sensitive organs. Adverse effects such as abnormal excretion of protein, glucose and amino acid in urine as a result of renal tubular dysfunction have been observed in humans.
  3. The Joint Food and Agriculture Organization / World Health Organization Expert Committee on Food Additives (JECFA) has evaluated the safety of cadmium and established a provisional tolerable monthly intake (PTMI) of 25μg per kg body weight (bw) to it. PTMI is an estimate of the amount of a contaminant that can be ingested over a lifetime without appreciable risk. An intake above the PTMI does not automatically mean that health is at risk. Transient excursion above the PTMI would have no health consequences provided that the average intake over long period is not exceeded as the emphasis of PTMI is a lifetime exposure.
  4. The International Agency for Research on Cancer (IARC) of the World Health Organization considered that there was sufficient evidence of carcinogenicity of cadmium and cadmium compounds in humans upon occupation exposure, and classified them as Group 1 agents. However, available evidence suggested that cadmium did not appear to have significant genotoxic and carcinogenic potential via the oral route.

Situation in Hong Kong

  1. Levels of cadmium in food in Hong Kong is regulated under the Food Adulteration (Metallic Contamination) Regulations (Cap. 132V) made under the Public Health and Municipal Services Ordinance (Cap.132), which stipulates the maximum levels for cadmium in food. Offenders shall be liable to a maximum fine of $50,000 and imprisonment for six months. Please refer to the designated webpage for details.

Advice to the Trade

  1. To observe good agricultural practices to minimise cadmium contamination in food crops, animals, poultry and fish.
  2. To obtain food supplies from reliable sources.
  3. To wash fruits and vegetables and peel roots and tubers can reduce cadmium contamination to some extent.

Advice to the Public

  1. To be vigilant in selecting your foods. Don't buy foods from dubious sources.
  2. To wash fruits and vegetables and peel roots and tubers can reduce cadmium contamination to some extent.
  3. To maintain a balanced diet so as to avoid excessive exposure to contaminants from a small range of food items. Fruit and vegetables are important components of a healthy diet as they are good sources of dietary fibre, vitamins and minerals.

Risk Assessment Section
September 2025