China's Pollution Crisis: Impacting Food Production And Sustainability

China's pollution is affecting its food production in a number of ways. Firstly, the country's food security is affected by large but inefficient chemical fertiliser and pesticide residue. Secondly, there is cropland heavy metal pollution, especially cadmium. Thirdly, there is water pollution, including general water pollution and sewage irrigation. Finally, there is air pollution, including ground-level ozone.

**Chemical Fertilizer and Pesticide Consumption**: China's overuse of chemical fertilizers and pesticides is a major source of persistent organic pollutants and endocrine disruptors, which can impair plant metabolism and contaminate crops

China's overuse of chemical fertilisers and pesticides is a major source of persistent organic pollutants and endocrine disruptors, which can impair plant metabolism and contaminate crops. China is the world's largest consumer of agricultural chemicals, using more than 30% of global fertilisers and pesticides on only 9% of the world's cropland.

The size of farms in China is a key contributor to the overuse of agricultural chemicals. Small farms often use chemicals inefficiently, leading to financial losses and serious local, regional and global pollution, from eutrophication to particle pollution in the air and global warming.

A 1% increase in farm size was found to be associated with a 0.3% and 0.5% decrease in fertiliser and pesticide use per hectare, respectively. This corresponded to an almost 1% increase in agricultural labour productivity and an insignificant decrease in crop yields.

The overuse of fertilisers and pesticides in China is also linked to the country's land and migration policies, which have distorted the relationship between economic growth and farm size. These policies have led to the persistence of small farm sizes, which are less able to adopt technological innovations and modern management practices that reduce the use of agricultural chemicals.

The Chinese government has made efforts to reduce the excessive use of agricultural chemicals, but the effects have been limited. To address this issue, the government should adopt policy combinations that address both the efficiency of chemical fertiliser use and the intensity of organic fertiliser use.

**Cropland Heavy Metal Pollution**: Heavy metal pollution in China's cropland is a salient issue, with about 10.18% of cropland polluted by heavy metals, and 13.86% of grain production affected

Cropland Heavy Metal Pollution

Heavy metal pollution in China's cropland is a salient issue, with about 10.18% of cropland polluted by heavy metals, and 13.86% of grain production affected.

Sources of heavy metal pollution

The main sources of heavy metal pollution in China's croplands are mining activities, pesticides and fertilisers, vehicle emissions and coal combustion, sewage irrigation and industrial waste.

Heavy metal pollution trends

Cadmium is the most prevalent pollutant in China's croplands, with increasing trends from 1990 to 2021. Mercury and copper are also increasingly present in China's croplands.

Regional differences in heavy metal pollution

Central and southwestern China are the most affected by heavy metal pollution, with provinces such as Hunan, Henan, Guangxi, Sichuan and Chongqing being particularly affected. Gansu and Liaoning in northern China are also seriously affected.

Health risks of heavy metal pollution

Long-term exposure to heavy metals can cause serious health issues, such as diarrhoea, abortion, hepatitis and typhoid.

**Water Pollution**: Water pollution, including general water pollution and sewage irrigation, is another concern, as pollutants in the water can be deposited in the cropland and transported to crops

Water pollution is a pressing issue in China, as it threatens food safety and public health. Water quality in China is becoming a severe challenge for agriculture and food safety and may impact the health of the population. The Second National Water Resource Survey in China shows that about 60% of groundwater is polluted. China is the largest consumer of fertilizer and pesticide in the world, and the amounts of application are still increasing. Fertilizers and pesticides are the most important sources of pollution, which affect human health as persistent organic pollutants and environmental endocrine disruptors. Eutrophication of surface water and nitrate pollution of groundwater are serious threats to drinking water safety. Sewage irrigation is becoming a pollution source to China's water and land because of a lack of effective regulations.

Water pollution in China is also caused by the long-term use of wastewater irrigation to fulfil water requirements for agricultural production. This has caused serious agricultural land and food pollution, especially from heavy metals. In some regions, this has caused serious agricultural land and food pollution, especially for heavy metals. China's per capita arable land area is less than half of the world average, and per capita arable water is about a quarter of the world average. As a result, the country cannot afford to lose any more available land or water due to increasing problems with pollution.

**Air Pollution**: Ground-level ozone pollution has been found to damage crops and reduce yields. China's ozone concentration has been rising faster than in other countries

Air pollution, especially ground-level ozone, is a serious threat to China's food security.

Ground-level ozone pollution has been found to damage crops and reduce yields. China's ozone concentration has been rising faster than in other countries, and the daily average concentration has reached over 50 parts per billion during the crop-growing season in some regions.

Ozone is a highly reactive oxidant that significantly reduces crop productivity as well as the uptake of atmospheric carbon by vegetation. Its effects on plants include impeded growth and seed production, reduced functional leaf area and accelerated ageing.

Studies have shown that many species of plants are sensitive to ozone, including agricultural crops, grassland species and tree species. These effects damage important ecosystem services provided by plants, including food security, carbon sequestration, timber production, and protection against soil erosion, avalanches and flooding.

China's agricultural development still relies heavily on agrochemical inputs, with the largest chemical fertiliser and pesticides consumption in the world. However, the utilisation efficiency is still much lower than that of developed countries. Intensive but inefficient agrochemical consumption produces a large amount of residue in soil and plants and brings a great challenge to the food safety of the country.

The high input and low efficiency have contributed substantially to the emissions of greenhouse gases such as methane and nitrous oxide, and the entry of pollutants into water bodies and soils, such as nitrogen and phosphorus, pesticide, and heavy metals, which would finally be transferred and accumulated in food.

China's food demand is projected to keep increasing in the coming decades, with a further increase in the reliance on food and feed imports. It is, therefore, necessary to assess the impacts of such growing demand on China's domestic environment, as well as the environment of its trading partners, to inform sustainable development policies.

China's increasing food demand, especially for livestock products (16-30% across all scenarios), would domestically require 3-12 million hectares of additional pasture between 2020 and 2050, resulting in -2% to +16% growth in agricultural greenhouse gas emissions. The projected 15-24% reliance on agricultural imports in 2050 would result in 90-175 million hectares of agricultural land area and 88-226 million tonnes of carbon dioxide-equivalent per year of greenhouse gas emissions virtually imported to China, which account for 26-46% and 13-32% of China's global environmental impacts, respectively.

The distribution of the environmental impacts between China and the rest of the world would substantially depend on the development of trade openness. Thus, to limit the negative environmental impacts of its growing food consumption, besides domestic policies, China needs to also take responsibility in the development of sustainable international trade.

**Food Safety Policies**: China has implemented policies to combat food security threats, such as the Action Plan for Zero Growth of Fertilizer Use by 2020 and Action Plan for Zero Growth of Pesticide Use by 2020

Food safety policies in China have been implemented to combat food security threats, such as the Action Plan for Zero Growth of Fertilizer Use by 2020 and the Action Plan for Zero Growth of Pesticide Use by 2020. These plans were introduced to reduce the overuse of chemical fertilisers and pesticides, which have been causing environmental pollution and threatening food safety.

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