The economic losses caused by soil and water pollution are mainly reflected in four aspects: agricultural production, infrastructure, public health, and ecosystems. In terms of agricultural production, the annual soil loss caused by soil erosion in China reaches 5 billion tons, including organic fertilizers such as nitrogen, phosphorus, and potassium equivalent to 40 million tons of chemical fertilizers, with a direct economic loss of about 2.4 billion yuan. Polluted irrigation water sources have led to excessive heavy metals in crops, such as cadmium contaminated rice, which has caused frequent incidents. This not only reduces grain production, but also significantly diminishes the market value of agricultural products. The Yangtze River, Yellow River and other river basins input 2.6 billion tons of sediment annually due to soil erosion, with organic matter content equivalent to the annual output of 50 large fertilizer plants. This nutrient loss directly weakens land productivity. Infrastructure losses are equally severe. Eight major water systems in Zhejiang Province have experienced a general uplift of 0.2-0.1 meters due to sedimentation, resulting in a reduction of 1000 kilometers in inland waterway mileage compared to the 1960s, and some waterways have been completely abandoned. Due to siltation, the surface area of Dongting Lake decreased from 3915 square kilometers in 1954 to 2740 square kilometers in 1978, and the flood storage capacity decreased by about 30%, exacerbating the flood control pressure in the middle and lower reaches of the Yangtze River.

The losses in the field of public health are more hidden but have far-reaching impacts. After heavy metals enter the food chain through contaminated soil, neurotoxins such as lead and mercury accumulate in the human body, which may cause chronic kidney disease, neurological damage, and even cancer. The incidence rate of skin cancer among residents in a certain area of Hunan Province is significantly higher than the national average level due to long-term drinking of arsenic bearing groundwater. The waterborne infectious diseases caused by water pollution result in huge medical expenses every year, such as the mass diarrhea incident caused by water source pollution in a certain province in 2016, where the cost of handling a single epidemic exceeded 8 million yuan. The degradation of ecosystem services has brought about a chain reaction, with some reservoirs in the Yangtze River Basin shortening their design life by 30-50 years due to siltation. According to predictions in the Sichuan Basin, based on the current siltation rate, most reservoirs will lose their regulating function within 50 years. The biodiversity of aquatic organisms has sharply declined due to pollution, and the mortality rate of grass carp and green carp in a eutrophic lake with an ammonia nitrogen concentration of 0.05mg/L within 72 hours has reached **, directly destroying fishery resources.

Composite pollution also leads to an exponential increase in treatment costs. According to data from the management of a small watershed on the Loess Plateau, repairing a 1 square kilometer area with severe soil erosion requires an investment of about 500000 yuan, and the resulting reduction in flood losses can save 1.2 million yuan in disaster relief funds annually. In order to ensure drinking water safety, the Yangtze River Delta region has invested over 20 billion yuan in the construction of advanced treatment facilities in the past five years. The more profound impact is reflected in intergenerational equity, where certain persistent organic pollutants such as dioxins have a half-life of several decades in soil, and the health damage caused by mother to child transmission will continue into the next generation. These multidimensional losses indicate that soil and water pollution is not only an environmental problem, but also a key bottleneck restricting sustainable economic and social development.