Extreme weather conditions such as long spells of drought followed by heavy rains is leading to toxicity of food, a recent report released by the United Nations Environment Programme (UNEP ) said.

Major food crops such as maize, wheat, soyabeans are reacting to unusual weather patterns by retaining nitrates, which are toxic for both humans and animals, the report said, according to theReuters.

During the normal process, plants absorb the nitrates and convert them into amino acids and proteins. However, under drought-like conditions, this process slows down leading to accumulation of nitrates in plants.

Nitrates have a detrimental effect on humans and can intervene with functioning of red blood cells that transport oxygen throughout the body.

“Crops are responding to drought conditions and increases in temperature just like humans do when faced with a stressful situation,” Jacqueline McGlade, chief scientist and director of the Division of Early Warning and Assessment at UNEP, was quoted by the Reuters as saying.

Plants have the ability to accumulate several other chemicals such as Prussic Acid, Aflatoxins in response to extreme weather conditions.

Prussic Acid or hydrogen cyanide poisoning cases in humans were reported in Kenya in 2013 and in Philippines in 2015.

The UNEP official told Reuters that nearly 4.5 billion people around the world are exposed to aflatoxins. These chemicals killed at least 100 people in Kenya in 2004 and 300 persons suffered aflatoxin poisoning.

“Toxic crops can lead to neurological diseases among humans but the greatest challenge is the incidence of cancer,” Alex Ezeh, executive director of the African Population Health and Research Center, was quoted by the Reuters as saying.