2. Rugao is located in the jianghai plain, and its natural geographical environment and social and economic activities are not closed. Therefore, Rugao's longevity cannot be explained by a single factor. Obviously, it is the result of the superposition of many factors, including natural factors, human factors and the reasons for the longevity of the elderly.
After more than two years of research, they also preliminarily believe that there are several factors that affect Rugao's longevity:
(1) Natural environmental factors:
1, mild temperature, comfortable and pleasant.
Rugao is located at 32 00 ′-32 30 ′ north latitude, and belongs to the humid climate zone in the north subtropical zone. The annual average temperature is 14.7℃, and the hottest average temperature in July is 27. 1℃. In recent 40 years, the lowest temperature was below-10℃ for only 7 days, and the annual average temperature was above 35℃ for only 5.4 days.
2. Adequate rain and moderate humidity.
The annual precipitation in Rugao is about 1 0,056.8 mm, and the average precipitation days are 1 0,654.38+0.9.4 days. The number of rainstorm days over 50 mm is only 3.2 days, and the annual average relative humidity is 80%, which makes people feel cheerful and energetic.
The air is fresh and green.
As Rugao enjoys superior climatic conditions, lush forests and green vegetation all year round, there are 500 ginkgo trees 1.500, 850 cypress trees, 800 pine trees, 300 Podocarpus, 300 boxwood trees and 300 five-needle pine trees in Rugao. These "living fossils" show Rugao's profound cultural heritage. Since ancient times, Rugao people have paid attention to the environmental greening of the courtyard and the arrangement of indoor bonsai, and have a good reputation as the bonsai capital of flowers and trees in China. Rugao ordinary farmers are "there are big trees in front, big bamboos in the back, and halls in the middle". They think that the number of trees is a symbol of wealth. Since ancient times, there has been a saying that "the poor people show meat and the poor villages show houses". Rugao is full of vitality, and the gardens in full of green beautify the environment, cultivate the mood, purify the air and increase the content of negative ions, which is a great enjoyment for people's body and mind.
4. Rivers crisscross and the water quality is excellent.
Rugao has a dense water network, criss-crossing rivers and connecting with the Yangtze River, rich drinking water sources and excellent water quality. Rugao people like to drink "Tianshui" when drinking tea, and they also like to use Pogostemon, Mint and Hedyotis diffusa (scientific name Plantago) instead of tea to cool off the heat. These traditional Chinese medicines have health-care functions such as dispelling summer heat and strengthening stomach. Now there are wells in rural areas, but tap water has been widely used in cities, and the "clear spring" project is being implemented in rural areas to popularize drinking tap water. According to the survey data of drinking water sources over the years, the compliance rate of drinking water sources in Rugao City is 98.5%. All the chemical indexes have been kept within Grade I-II standards. The human body is rich in trace elements such as iron, manganese, zinc and selenium, while some trace elements such as manganese and iron exceed the standard. According to literature, manganese has lipophilic, anticancer and anti-aging effects in human body, and moderate high manganese is beneficial to human health.
5. The soil resources are diverse and rich in products.
The main source of Rugao soil is the Yangtze River alluvium, which is influenced by the Huaihe River alluvium, which makes the mineral composition of Rugao soil parent material more complicated and lays the foundation for the diversity of soil element composition. The complex soil resources form Rugao's rich foundation planting resources, which lays a solid foundation for the diversity of Rugao's plant resources.