Overview of the ecological environment of the Northwest Shandong Plain

1. Overview of the ecological environment

(1) Current status of the ecological environment

1. Utilization and degradation of land resources

Land is where all things grow It is the foundation of human life and work, and the basic resource for human survival. Without the land, we lose the basic conditions for survival, so protecting the land is to protect human beings themselves. There are large regional differences in soil and water loss in the plain area of ??northwestern Shandong, which are highlighted in land loss, soil salinization, land desertification, and an increase in non-agricultural land.

(1) Land loss

The survey area is located in the lower reaches of the Yellow River. It mainly receives soil deposited by surface water from the middle and upper reaches of the Yellow River and the mountainous areas of central and southern Shandong. However, since 20 At the beginning of the 20th century, due to natural factors, surface water was plentiful and it was washed away by floods, causing land loss to an area of ??100.83×104 hm2, accounting for 13.62% of the land area of ??the working area, of which 28.23×104 hm2 was lost to cultivated land and 8.53% was lost to grassland. ×104 hm2. Areas with soil and water loss areas of 15×104 to 20×104 hm2 are mainly distributed in Dongying, Binzhou and Dezhou, and Heze has the smallest water and soil erosion area. With the increase in forestry planting area and effective land protection measures, after entering the 21st century, the area of ??land loss has significantly decreased in most areas, with only a slight increase in the area of ??land loss in Dongying and Binzhou.

(2) Land salinization

The salinized land in the survey area is mainly distributed in Dongying, Jining, Binzhou, Dezhou and other regions. The area of ??salinized land is about 38.85×104 hm2 , accounting for 27.73% of the province's salinized land area. The largest salinized land area in Binzhou City is about 15.87×104 hm2; the smallest salinized land area in Heze City is about 2100 hm2. Dongying City is also an area prone to varying degrees of salinization, with a small area of ??cultivated land. Overexploitation of groundwater has led to seawater intrusion, aggravating and accelerating the process of soil salinization. From 1970 to 2000, the salinized land area in the survey area increased by 55.7×104 hm2, with an average annual increase of about 1.86×104 hm2. The salinized land area in Dongying City increased the fastest, from 7.78×104 hm2 in 1986 to It increased to 13.87×104 hm2 in 2000, an increase of 78.28. Due to large storm surges and seawater erosion, a large area of ??cultivated land in Dongying City was damaged, resulting in 2283.4 hm2 of cultivated land being degraded into unused land, and another 2847.6 hm2 of cultivated land being degraded into saline land year by year due to secondary land salinization.

(3) Land desertification

The survey area is a yellow flood plain. The special topography has resulted in large areas of desertified land in Heze, Liaocheng, Dezhou, Binzhou and other areas. There are 24.28×104 hm2 of desertified land, accounting for 39.59% of the province’s desertified land; in particular, Dongying City has the largest area of ??desertified land, 15.9×104 hm2. Due to the continuous expansion of land desertification, governments at all levels have realized the importance of protecting the ecological environment. In recent years, they have increased the greening area and brought the desertification phenomenon under control. The area of ??desertified cultivated land has decreased by 5.91%, and the area of ??desertified grassland has decreased by 69.49%.

(4) Increase in non-agricultural land

With the rapid development of the economy, the phenomenon of land occupation has become more serious. According to the 2004 "Comprehensive Statistical Report on Land and Resources": the construction land in the survey area is 119.11 ×104 hm2, residential and industrial and mining land is 99.19×104 hm2, transportation land is 7.25×104 hm2; water conservancy facility land is 12.84×104 hm2, unused land is 50.98×104 hm2, and the total non-agricultural land is 289.38×104 hm2. Heze is the city with the most construction land, 18.86×104 hm2. It is also an area with more residential, industrial, mining, and transportation land. The areas with smaller non-agricultural land are Jinan, Tai'an, and Zibo. But in general, non-agricultural land is the main reason for the loss of cultivated land.

2. Development and utilization of water resources

Water is the source of growth for all things and the basic guarantee for the survival of life. With the influence of economic development and human factors, water resources have been polluted to varying degrees, which has brought great inconvenience to people's normal lives and restricted social and economic development. The survey area is an area lacking water resources.

(1) Surface water resources

The surface rivers in the survey area are controlled by geological structures and topography. The rivers generally flow from south west to northeast, and the water volume of the rivers is to supply the work in the area. The main water source for agriculture and people's normal life, the abundance and shortage of river water directly affects the economic development of the area and the people's normal life. There are many rivers in the area. The main rivers include the Yellow River, Tuhai River, Majia River, Xiaoqing River, Beijing-Hangzhou Grand Canal, Xinwanfu River, Dongyu River, etc.

The lakes are mainly distributed in the contact zone between central and southern Shandong and northwest Shandong plains. It is divided into two major lake groups with Jining City as the center. To the south is Nansi Lake (Nanyang Lake, Dushan Lake, Zhaoyang Lake and Weishan Lake) with an area of ??about 1178 km2. It is one of the ten largest freshwater lakes in my country. To the north is Nansi Lake. The five northern lakes, except Dongping Lake, have all silted up into low-lying areas where water accumulates in summer. Due to natural factors, there was a drought in 2002, and Nansi Lake dried up for nearly three months. In addition to causing serious damage to the economy, it also seriously damaged the ecological environment of the lake area and surrounding areas. The pollution along the lake is also very serious, with the annual pollution amount reaching 13650×104 t. The main pollutants include suspended solids, chemical oxygen demand, biochemical oxygen demand, hexavalent chromium, phenol, cyanide, petroleum, sulfide, Ammonia, nitrogen and aniline all exceeded the standard. There are 245 major polluting enterprises along the lake. In order to control the polluting enterprises, the provincial government has increased its efforts. The pollution situation has been controlled to a certain extent, and the ecological environment has developed in a good direction.

(2) Groundwater resources

Due to the development of Cambrian and Ordovician limestone strata in the southern mountainous area of ??the survey area, the karst landform is conducive to the storage of groundwater, especially in large areas of thick limestone. In the mountainous areas of southern Jinan, karst fissures are developed, which is conducive to precipitation infiltration. The alluvial plain of the Yellow River in northern Shandong and southwest Shandong has a flat terrain, which is conducive to the infiltration of atmospheric precipitation. The areas along the Yellow River mostly receive lateral seepage water supply from the Yellow River.

In recent years, with the development of industry and agriculture and the improvement of people's living standards, the amount of groundwater extraction has shown an increasing trend. Geological disasters caused by groundwater extraction are frequent, and environmental problems such as seawater intrusion, ground subsidence, and increase in ground fissures are becoming more serious.

(3) Water resources pollution status

According to statistics from the Provincial Environmental Protection Bureau in 2000, the total annual wastewater discharge in the survey area was 72 358×104 t, and the wastewater discharge standard was 66009× 104 t, with a compliance rate of 88 (the compliance rate increased by nearly 45 percentage points compared with 1995 in the 20th century). The wastewater discharge amounts of Jining City and Zibo City reached 12 984 × 104 t and 10 279 × 104 t respectively, accounting for 10% of the total wastewater discharge in the region. 32.14 of total emissions. In recent years, the district's sewage and wastewater discharge compliance rate has increased year by year, increasing by nearly 60 percentage points from 1990 to 2000. The pollutants in sewage and wastewater mainly include chemical oxygen demand, suspended solids, volatile phenol, sulfide, cyanide, petroleum, arsenic, hexavalent chromium, lead, cadmium and mercury, among which chemical oxygen demand, suspended solids and Sulfide accounts for the largest proportion and is a major pollutant. From an industry perspective, paper making and paper products, food, beverage and tobacco manufacturing, chemicals, textiles, medicine, minerals, leather, fur and their products are the most polluting industries.

River water pollution comes directly from the influence of industry, agriculture, and human factors. With economic development and the pursuit of economic benefits by enterprises, river water pollution has become increasingly serious. The rivers in the survey area have been polluted by 100%. In addition to industrial pollution, shallow groundwater is also polluted by agriculture. Agricultural pollutants mainly include "trinitrogen", organophosphorus, organochlorine, etc. Areas with serious shallow groundwater pollution are mainly distributed along the sewage rivers, towns and industrial areas, including Jinan, Dongying, Dezhou and Liaocheng. From the testing data, it is known that the pollution factors are mainly mercury, phenol, chemical oxygen consumption, etc.

3. Vegetation ecological environment

(1) Forest resources

The survey area is located in the alluvial plain of the Yellow River and is mainly agricultural production. In addition, in the 1980s At present, deforestation incidents occurred frequently, resulting in large areas without forests. The forest coverage rate is much lower than the national average, with Shandong Province having the lowest rate. Since the 1980s, governments at all levels have attached great importance to forestry, and the policy of returning farmland to forest has been further implemented. The forest coverage rate has shown a slow recovery trend, rising from less than 1.9 to 11.45 in 2000. In particular, the forest coverage rate in Heze reached 16. Dongying City has the lowest area with only 2×104 hm2. Since Dongying City is eroded by saline soil and sea water, the forest survival rate is extremely low, which greatly affects the development of forestry. In the 21st century, with the further implementation of the policy of returning farmland to forest, afforestation and forest protection have been implemented at the grassroots level to ensure the development of forestry and the forestry area continues to increase. In recent years, the awareness of environmental protection has been continuously strengthened, and the love and protection of birds has led to the large-scale breeding of birds, which has added natural protection to forestry pest control.

(2) Grassland resources

Grassland is mainly distributed in coastal plains, inland saline-alkali sand wastelands and rivers and lakes swamps. It is mainly pasture grassland and is mainly distributed in northwest Shandong In plain areas, especially in the sparsely populated Yellow River Delta, most of these pastures are natural grasslands, and there are also artificial grasslands, fenced grasslands, and rotational grazing grasses.

In the 1980s, in order to increase cultivated land, non-agricultural land occupation increased, and the grassland area decreased significantly, causing losses to wetlands and the ecological environment. Since the late 1990s, when farmland was returned to grassland to protect wetlands, the grassland area has been on the rise. The largest grassland area is in Dongying, followed by Liaocheng. According to relevant information, the increase in the number of livestock has caused varying degrees of damage to grassland. The grassland in the Yellow River Delta has been affected by rodent damage, industrial occupation, etc., and the grassland area has been relatively reduced.

4. Coastal ecological environment

The rise in global temperatures has caused the melting of glaciers and ice caps, causing sea levels to rise, causing the sea level to rise at an average rate of 1 to 2 mm per year, accelerating the Erosion and flooding of land. Storm surges also accelerate seawater erosion of coastal zones. On August 20, 1997, a storm surge occurred in the Hekou District of Dongying City, causing the seawater to cross the high tide line and flood a large area in the northern part of the Hekou District for 60 hours. The trees in the forest farm All destroyed. The coastline of the survey area is about 201km, and coastline changes are directly affected by seawater invasion.

(1) Coastal erosion

Coastal erosion refers to the erosion of the coast by ocean forces such as nearshore waves and tidal currents, as well as the detrital materials and certain chemically reactive materials they carry. The destructive effects of coastline recession caused by erosion, abrasion and dissolution, etc., cause coastal erosion to be extremely harmful to residential areas and engineering facilities in the coastal zone. Except for siltation within 20 km near the modern estuary, other coastal sections near the Yellow River Delta are dominated by erosion.

The sediment content of the Yellow River is the main reason for the rapid land creation in the Yellow River Delta. Years of observations show that before the 1980s, the Yellow River had abundant water and sediment, with an average annual inflow of 320.86×108 m3 into the sea. The amount of sand is 746×108 m3 t. Within a certain length and width of the Yellow River estuary, the average multi-year reclamation and land reclamation is 40 km2/a, and the coastal erosion is 10-15 km2/a. Since the 1990s, due to the decrease in runoff in the lower reaches of the Yellow River, the flow interruption phenomenon has intensified. In addition, the development of water and soil protection work in the middle and upper reaches of the Yellow River and the flood control and sand storage function of the Xiaolangdi Reservoir Project have led to a significant reduction in sand volume. From the 1990s to the present, the average annual amount of sand entering the sea from the Yellow River is 3.64×108 t, which is only 28% of the amount of sand entering the sea in the 1950s. The sharp decrease in the amount of sand entering the sea from the Yellow River has broken the necessary conditions for maintaining a balance between coastal siltation and erosion, causing the coast of the Yellow River Delta that was originally dominated by siltation to become dominated by erosion under the action of sea dynamic factors. If allowed to develop, , the coastline in the delta area continues to recede, which will not only have a huge impact on Shengli Oilfield, the national high-efficiency ecological and economic development demonstration zone, but also have a devastating impact on the natural conditions of the entire Yellow River Delta wetland.

(2) Coastal sedimentation

The coastal sedimentation in the survey area is mainly near the estuary of the Yellow River. About 80% of the sediment brought into the estuary area by the Yellow River every year is deposited on land and in the coastal areas. In this area, less than 20% of the sediment volume is transported to the sea. Such a huge amount of sediment transport makes the Yellow River Delta famous for its rapid sedimentation. At present, the coastal sedimentation of the Yellow River Delta is mainly distributed in the area near the estuary. From 1976 to 1996, 434.3 km2 of land was created, and the land creation rate was 21.7 km2/a, of which the land creation rate from 1976 to 1985 was 32.3 km2/a. From 1985 to 1996, it was 13.1 km2/a, reflecting the decrease in the rate of land creation due to the decrease in the flow of the Yellow River in recent years.

The coastal siltation of the Yellow River Delta makes the growing shallow beach particularly suitable for the growth of marine life. The siltation land provides a broad space for the development of Shengli Oilfield; at the same time, the instability of the tail end of the Yellow River has also affected the production layout of the oil area. had adverse effects. In addition, the spread of sediment from the Yellow River into the sea will inevitably cause siltation in the waterways of Guangli Port, Dongying Port and Yangjiaogou Port.

(3) Tidal flat development and mariculture

In 2000, the tidal flat area of ??Dongying City was 48×104 hm2, which was the largest tidal flat area in the province. Compared with 1986, the area increased 13×104 hm2, Binzhou City increased by 25×104 hm2. Among them, Binzhou City has the highest intensity of tidal flat reclamation, with approximately 11.52×104 hm2 of tidal flat area reclaimed. Dongying City has zero tidal flat reclamation in order to protect the Yellow River Delta Nature Reserve. Marine culture is only distributed in Dongying and Binzhou, with a culture area of ??about 12.48×104 hm2. Due to the oil development in the Bohai Bay, marine aquaculture has been subject to certain restrictions in recent years. The area of ??marine aquaculture has increased, but the extent is small. Tidal flat development and marine aquaculture are seriously eroded by red tides and oil spills. Red tides are concentrated in the southwest of Bohai Bay, mainly in Binzhou and Dongying sea areas. Red tides occurred three times in the 1970s. As the coastal waters of the Bohai Sea became increasingly polluted and the seawater became hypoxic, the frequency of red tides increased, their impact range was wide, and their duration and environmental hazards showed an increasing trend. The root cause of red tide is that seawater is seriously polluted and the oxygen in seawater is greatly reduced. The algae of red tide prefer to grow and develop in anoxic and turbid and polluted seawater environment. The root cause of red tide is seawater pollution and lack of oxygen, so it is necessary to control the seawater ecological environment. The task is also very difficult.

(4) Seawater intrusion

Seawater intrusion is one of the geological disasters in the coastal zone and is extremely harmful. It is highly concealed and difficult to control. The main cause of seawater intrusion is natural factors and man-made factors. Changes in important hydrodynamic conditions in coastal areas have destroyed the relative balance between underground freshwater and seawater, causing seawater to move inland, worsening groundwater quality, and destroying the ecological environment.

In addition to natural factors, seawater intrusion is mainly caused by human factors. Due to years of over-exploitation of groundwater, a groundwater funnel is formed, causing saltwater intrusion, depletion of the upper aquifer, reduction of water output from a single well, and loss of mining depth. The increase has caused deep groundwater to suffer from different seawater intrusion phenomena. Seawater intrusion leads to the deterioration of groundwater quality, secondary soil salinization and decrease in soil fertility, which in turn leads to reduced agricultural production, scrapping of motorized wells, and serious damage to the ecological environment of the coastal plain. Many farmlands in the invaded areas were abandoned and became barren land.

(2) Existing ecological environment problems

The quality of the ecological environment is restricted by many factors, including geological environment, regional water pollution, land degradation, forest secondaryization and meteorology. In addition to controlling conditions and other conditions, it is also affected by human factors brought about by economic development.

Under the tide of economic development, the development of industry and agriculture emphasizes development and neglects governance, focusing on benefits and neglecting the long-term, causing serious damage to the ecological environment. The development of industry and agriculture is the place where human activities have the strongest impact on the geological environment. While humans develop and utilize the minerals and water resources buried underground, they also change and destroy the ecological environment. Industrial and agricultural production activities include mineral extraction, industrial and agricultural sewage discharge, and excessive exploitation of groundwater resources.

Due to the above-mentioned activities, underground mining, groundwater depletion, sewage discharge and man-made geological effects have caused a series of geological disasters and ecological environment problems.

The main ecological and environmental problems existing in the survey area include: land subsidence, ground fissures, land salinization, land desertification, soil erosion, seawater intrusion, water pollution, coastal erosion and coastal sedimentation. These ecological and environmental problems have caused great harm and inconvenience to industrial and agricultural production and human activities in the region. For example, land subsidence in Jining has been increasing year by year, and the scope of subsidence has expanded accordingly. In addition to large agricultural areas affected by land subsidence, crop yields have been reduced in large areas, soils have been degraded, and salinization has increased, seriously threatening the development of agriculture. What is even more serious is that in the urban area of ??Jining, west of Jianshe Road, east of Taibailou West Road, and east of Jianqiao Road, the ground subsidence has reached 80mm, with the maximum subsidence point reaching 140.5mm. The ground subsidence has directly affected urban construction and housing. Cracks appeared, the road collapsed, and even the ancient building Taibai Tower was not spared, causing great harm to people's normal life.

The fragile natural ecological environment is subject to interference and damage from multiple factors. The ecological environment has seriously endangered human beings' normal work and life, and it is urgent to control the ecological environment.

2. Overview of the distribution of endemic diseases

According to relevant data, the endemic diseases related to the environment in the region mainly include: endemic goiter (endemic goiter), endemic fluorosis (endemic fluorosis) Fluorosis), Keshan disease and Kashin-Beck disease.

(1) Goiter

Endemic goiter is a global disease, mainly caused by the lack or excess of iodine in the geological environment, which is related to geochemical elements. related diseases. When the body's intake of iodine is unbalanced, it will lead to biochemical dysfunction and abnormal physiological function of the human body. Symptoms include goiter, thickening of the neck, stagnant physiological development, abnormal cell metabolism, and underdevelopment of the central nervous system. In severe cases, symptoms such as short stature and paralysis may occur, seriously endangering human health. As an essential trace element for the human body, iodine must be stable within a certain, or appropriate, range. People with urinary iodine below 100 μg/L are called iodine deficiency; urinary iodine between 100 and 200 μg/L is the optimal state of iodine nutrition; urinary iodine exceeding 300 μg/L is called "higher than the appropriate amount"; urinary iodine exceeding 500 μg/L is called "higher than the appropriate amount". The incidence of iodine-induced hyperthyroidism increases in the population at L. According to the cause, onychomycosis can be divided into: iodine-deficient endemic goiter and iodine-high goiter.

1. Iodine-deficient endemic goiter

This disease is caused by long-term iodine deficiency. Under normal circumstances, each person's daily intake of iodine 100 to 250 mg can meet the needs. <100 mg/L, cretin patients with mental retardation, deafness, and short stature like a dwarf may appear. The disease is concentrated in the middle and low mountains and hills and alluvial plains. According to relevant data in 2000, the survey areas are mainly distributed in Guangrao County and northern Weifang in the alluvial plains. The total number of sick people is 28,800, including Keting. There were 81 patients, and the disease also occurred in Jining area.

2. High iodine goiter

In accordance with the national standard "Delimitation of Waterborne High Iodine Areas and Local High Iodine Goiter Disease Areas" (GB/T19 380-2003), The concept of high-iodine areas refers to areas in a specific natural environment where people's long-term intake of iodine through drinking water significantly exceeds the physiological needs of the human body, but is not enough to cause the prevalence of high-iodine goiter. The delineation standard is that (on a township basis) the iodine content of residents' drinking water is >150 μg/L; the median urinary iodine content of children aged 8 to 10 years is >400 μg/L. The concept of high-iodine disease areas is that in a specific natural environment, people have long-term intake of excessive iodine through drinking water, which causes goiter and forms endemic high-iodine goiter. The delineation standards (based on townships) are that the iodine content of residents' drinking water is >300 μg/L; the median urinary iodine level of children aged 8 to 10 years is >800 μg/L; and the goiter rate of children aged 8 to 10 years is >5.

High iodine causes changes in the body's thyroid morphology and function, causing thyroid autoimmune diseases such as goiter, hyperthyroidism, hypothyroidism, and Hashimoto's thyroiditis. The harm of high iodine has now become a serious public health problem in our country.

Shandong Province is one of the provinces most seriously affected by high iodine in my country. According to a survey conducted by the Shandong Provincial Institute of Endemic Disease Prevention and Control in 2003-2004, high iodine disease areas and regions are distributed in 7 cities and 38 There are 288 towns and villages in every county (city, district), with a threatened population of 14 million. In terms of the distribution range of high-iodine areas, the survey area is located in two large-scale high-iodine areas in Shandong Province. One is the alluvial, marine and lacustrine plains near the mouth of the Yellow River, and is bordered by the Bohai Sea in the east, including Hebei and Shandong. The 12 counties in the two provinces are deep-water high-iodine areas; the second area is the area between the Yellow River and its old course, including parts of northern Shandong and southwestern Shandong, which is a shallow-water high-iodine area. All high-iodine areas and high-iodine disease areas in Shandong Province are located in this survey area.

There are 17 high-iodine areas in the survey area based on counties, including: Gaoqing County, Decheng District, Leling City, Ling County, Ningjin County, Xiajin County, Wucheng County, and Liangshan County , Linqing City, Shen County, Chiping County, Guan County, Mudan District, Cao County, Shan County, Juye County, Yuncheng County, Juancheng County, Dingtao County and Dongming County, etc. The coast is mainly concentrated in the Bohai Plain in northern Shandong, and the inland is mainly concentrated in the southwest plain of Shandong, the lower reaches of the Yellow River and both sides of the Beijing-Hangzhou Grand Canal.

(2) Endemic fluorosis

Endemic fluorosis is a geochemical disease that occurs in a specific geographical environment. It is a chronic cumulative poisoning of the whole body caused by people living in a high-fluoride environment for a long time under natural conditions. It is mainly caused by excessive intake of fluoride through drinking water, air or food and other media. It is commonly known as "big yellow teeth" and "gangou teeth". ”, “diabetic bone disease” and “black bone disease” etc. Shandong Province is one of the provinces in the country that is most seriously affected by endemic fluorosis. The disease area is wide, the disease is serious, and the harm is great. People in endemic fluorosis wards drink high-fluoride water, which can cause dental fluorosis in mild cases, skeletal fluorosis in severe cases, and even lead to paralysis and loss of working ability, which seriously endangers the health of the people in the ward. Directly affects the economic and social development of the ward. Shandong Province is a drinking water-type endemic fluorosis disease area. The disease areas in the province are distributed in 11,656 villages in 113 counties (cities, districts) in 17 cities. The affected population in the disease area is more than 9.79 million, and 2.9 million people suffer from dental fluorosis. There are more than 10,000 people, and more than 230,000 people suffer from skeletal fluorosis.

Endemic fluorosis in the region is mainly distributed in Dezhou, Binzhou, Jining, Zibo and Weifang, involving 48 counties (cities, districts) in 9 cities. ***There are 6,701 endemic fluorosis villages, including 3,935 villages with mild disease (water fluoride 1.01-2.00 mg/L), 2,437 villages with moderate disease (water fluoride 2.00-4.00 mg/L), and villages with severe disease (water fluoride 2.00-4.00 mg/L). Fluoride >4.00 mg/L) 329, with a population of 5.655 million affected. Fluoride-affected villages accounted for 57.49 of the province's total, and the affected population accounted for 57.76 of the province's population. The shallow groundwater in southwestern Shandong is mostly high in fluoride, while the shallow groundwater in northwestern and northern Shandong is mainly brackish and the deep groundwater is high in fluorine.

Since the early 1980s, Shandong Province has carried out local fluorosis prevention and control work with water improvement and fluoride reduction as the main measures (mainly digging wells), and has achieved certain results. In the survey area, 4,188 villages affected by water fluoride have undergone water improvement and fluoride reduction, benefiting more than 3.54 million people. The improved water villages accounted for 62.50% of the villages affected by fluoride in the survey area, and the beneficiary population accounted for 62.60% of the affected population in the survey area. Survey results in recent years show that the scrap rate of water improvement projects is more than 30%, and the water fluoride exceeding standard rate of projects that are basically operating normally is also more than 30%. In fact, the water improvement and fluoride reduction projects that meet drinking water hygiene standards are less than 50%, that is, the water fluoride reduction projects have been improved. Less than half of the diseased villages can actually drink low-fluoride sanitary water, and the prevention and control situation is still very serious.

(3) Keshan disease

Keshan disease is an endemic cardiomyopathy whose cause is not yet fully understood. The disease is widespread and has a high mortality rate, seriously endangering people's lives and health. The survey area has a small distribution range and a low incidence rate, and is mainly distributed in local areas of Jining and Weifang City. There are currently 1,500 sick people in Jining City, and the incidence rate is on a downward trend, mostly in the areas around Nansi Lake. Keshan disease in Weifang City is mainly distributed in the contact area between low mountains and plains. According to data from the Weifang Endemic Diseases Office in 2000, there are currently only 14 patients.

(4) Kashin-Beck disease

Kashin-Beck disease harms the human body’s bones and joint systems. Patients’ joints swell, they sway left and right when walking, and they have difficulty moving. In severe cases, their limbs are short and deformed. Even disabled. The main cause of Kashin-Beck disease is long-term drinking of seriously polluted kiln water. Calcium deficiency, low magnesium, selenium deficiency, high humic acid, and Fusarium in food may all be directly related to the onset of Kashin-Beck disease. The disease was found in very few places in the survey area, and was only found in Weifang. According to information provided by the Office of Endemic Diseases, there were 856 patients in 2000, including 2 newly discovered patients. The incidence was mainly in children.

The occurrence of endemic diseases is closely related to the water environment. It has a great causal relationship with the content of elements in the water and the lack of certain elements. Changing the quality of drinking water is a key factor in solving this problem, so creating an excellent Water quality and ecological environment are the basis for eradicating endemic diseases.