Pesticides and other chemicals in food

Chemicals such as pesticides, antibiotics and hormones are used in plant and animal farming to boost production, reduce food waste and help ensure an adequate food supply. In many countries, food safety regulators set maximum allowed limits for agricultural and veterinary chemical residues in food, covering both locally produced and imported products.

The residue levels permitted in food are set to be safe and to represent the lowest practical level, in line with good industry practice.

Why these chemicals are used#

Pesticides can dramatically increase crop yields and improve the quality of produce. However, they are also toxic chemicals designed to kill agricultural pests, and some can cause harm if consumed by people in large amounts.

In animal farming, drugs such as antibiotics and hormones are used to promote growth and reduce the amount of feed required. Residues of these drugs can also be hazardous to people.

The level of harm from exposure to pesticides, animal antibiotics and hormones is dose related: the more you are exposed to, the greater the potential risk.

Pesticide residues in fruit and vegetables#

Pesticide residue levels in fruit and vegetables are closely monitored in many countries. For most pesticides, a minimum time between spraying and harvesting is set to help ensure food is safe to eat. Monitoring programs consistently find residue levels to be very low and well within safe limits.

The amount of pesticide residue in food depends on many factors, including:

• The type and amount of pesticide used
• The amount of rain, wind and sunshine the crop received
• The kind of processing the food undergoes (such as storage time, washing or peeling)

The challenge is to balance a reliable, high-quality food supply with the need to protect consumers from unnecessary exposure to chemicals. Maximum limits for safe human consumption include wide safety margins.

In the past, a pesticide that was thought to be safe sometimes turned out to have undesirable effects. One example is DDT (dichlorodiphenyltrichloroethane), which persists in the environment and can accumulate in body fat. DDT is no longer used in crop production in many countries, though it is still used in some.

Antibiotics in animal farming#

Antibiotics are drugs that kill bacteria. In animal farming they are used to keep animals healthy, promote growth and cut down the amount of feed required. Over-use of antibiotics may increase the chance of breeding antibiotic-resistant strains of bacteria.

Regulations are generally in place to ensure animals are not given antibiotics in the few weeks leading up to slaughter, which helps reduce the amount of antibiotic residue left in the meat. There are also some concerns that antibiotic residues in milk may make people who are already susceptible more sensitive to penicillin.

Hormones in animal farming#

Sex hormones such as oestrogen and testosterone are used in some cattle farming to accelerate weight gain so animals can be sent to market earlier. Where they are used, their use is typically tightly regulated to help ensure they are safe for consumers and not harmful to the animals.

Eating meat that contains unacceptably high levels of hormones can lead to side effects in people, including breast enlargement and ovarian cysts.

Eating organic produce#

Organic farming grows produce without the use of synthetic chemicals or pesticides. However, organic food is not necessarily completely chemical free, because organic farmers may use natural pesticides on their crops. Even naturally occurring pesticides can cause problems if consumed in large amounts. Organic produce is also subject to food safety regulation so it can be eaten safely.

Reducing your exposure to pesticides and chemicals#

To reduce your exposure to pesticides and other chemicals:

• Choose organic produce if you prefer
• Thoroughly wash all fruit and vegetables, even organic ones
• Peel vegetables or remove the outer layer of leaves
• Trim visible fat from meat, as many residues are fat soluble
• Cook meat and poultry thoroughly
• Vary your protein sources, including alternatives such as legumes, tofu, nuts and eggs, to reduce your overall intake of antibiotic-resistant bacteria, hormones and pesticides

Chemical sensitivities and food#

Some people are more sensitive than others to pesticide residues. However, allergic reactions and sensitivities to naturally occurring chemicals, such as those found in eggs, shellfish, milk and nuts, are much more common.