Excessive application of nitrogen fertilizer is not good for ecology, what is the harm of excessive application of nitrogen fertilizer on human body?

Excessive nitrogen fertilizer for fruits and vegetables, beware of cancer. Have you heard of it? Now the food safety is getting weaker and weaker, so we must pay more attention to it ourselves.

Although eating fruits and vegetables is good for health, excessive use of nitrogen fertilizer and nitric acid in leafy vegetables can cause diseases such as esophageal cancer, gastrointestinal cancer and liver cancer. Cheng Cheng-yung, a professor of horticulture at National Taiwan University, points out that if there is no nitrogen fertilizer, crops will not grow, but any nitrogen-containing organic matter or chemical fertilizer in the soil will first be decomposed and oxidized into smaller molecular weight nitrate ions, commonly known as nitrate ions or nitrates. Animals can cause mild or severe toxicity if they eat plants that contain too much nitrate. the most obvious example is the "blue baby" caused by the intake of large amounts of nitrate, which can cause breathing difficulties and even suffocation.

As countries around the world have gradually set norms for the content of nitrate in vegetables, but the standards vary according to the zone or the length of day and night. For example, European countries only require 1500 to 2000 ppm for most vegetables, but recently the mainland has made stricter requirements, setting most vegetables below 450 ppm, which is a very high standard, but so far, Taiwan has not paid attention to this problem. In winter, some vegetables contain as much as 3, 000 to 4, 000 ppm nitrate.

Advanced countries have gradually regulated the concentration of nitrate in vegetables to protect consumers. For example, Germany stipulates that the content of nitrate in spinach for babies should not exceed 250 ppm. The safe dose announced by the World Health Organization (WHO) is 3.65 milligrams per kilogram of body weight per day, that is, a person weighing 60 kilograms can eat about 220 milligrams of nitrate a day. Therefore, if you eat half a jin (300g) of vegetables a day, the content of nitrate in vegetables should not be higher than 670 ppm. If you eat 400g, the content should be less than 500ppm.

Peng Wang Jiakang, academician of the Academia Sinica and director of the National Cancer Research Group, believes that in the past, China did not set a standard for nitrate in leafy vegetables, mainly because most farmers still use animal manure as fertilizer and rarely use chemical fertilizer. In recent years, there have been more cases of using chemical nitrogen fertilizer, and only the risk of cancer caused by nitrate can only be accumulated over a long period of time, so she does not advise children to be vegetarian, because children are at higher risk of being vegetarian, and the nutrients they need for growth will be insufficient.