In addition, some biologists also put forward a view that was difficult for the people of the time to accept, arguing that the external environment was full of dangers and the domestic environment was still not peaceful (it would take 47 years for the roving horse bandits to be eliminated, and the political movement also reduced the sense of security of the people, although the intensity and breadth were much lower than in history). It stimulates the self-preservation mechanism in the human gene, which greatly enhances the ability to reproduce, and uses many biological examples as evidence.

Although this argument was difficult to accept in China at the time, and the way these biologists compared animals to humans was even more difficult for some of the less educated cadres and masses to accept, so that many of them were shocked by this, if Hu Weidong had not come to his aid knowing that what they were saying was not nonsense, China's animal behavior research would probably have come to a long-term standstill. In fact, if it were not for the influence of this special factor, it would have been impossible for China to have a terrifying birth rate of more than 5% every year for the eight years from 1940 to 1947

However, the more important reason for the population explosion is the rapid decline in the mortality rate of the population, in the Republic of China period, due to the frequent wars and disasters and the serious corruption of the government, the people are not able to make a living, and there are at least several million people dying unnaturally every year, and after the founding of the People's Republic of China, the domestic peace has been achieved, and the water conservancy construction vigorously promoted by the government has greatly enhanced the country's ability to prevent and resist disasters, so that the harm of natural disasters has been greatly reduced

Deaths from starvation and war have almost completely disappeared, and the rapid improvement of medical standards and the establishment of a public health system in New China have contributed even more. In 1943, China ranked first in terms of antibiotic production and use. As a result, most bacterial infectious diseases are no longer a fatal threat to Chinese, and the cure rate of other diseases has also increased to varying degrees.

In addition, the training and introduction of surgeons (mainly from Japan) has also greatly reduced the infant mortality rate and the maternal mortality rate, which is actually the most influential factor, and it is worth mentioning that the decline in maternal mortality has in fact greatly increased the birth rate, especially on population growth.

The promulgation of the "National Nutrition Regulations" and the development of the national fitness campaign are "two-pronged", which enhances the physical fitness of Chinese, and thus enhances immunity, and the probability of getting sick is naturally further reduced. But neither nutrition nor exercise can pay off quickly, for now. The greatest impact is still the national health campaign marked by the "elimination of the four evils".

Although in the early days, due to a lack of biological knowledge, sparrows were also included in the four pests. However, due to the quick correction, it did not cause the historical almost extinction of sparrows, and mosquitoes, flies, rats and bed bugs were largely controlled, although they could not be completely eradicated. At least it's hard to see indoors in big cities. So much so that some female people's representatives have even proposed replacing bed bugs with cockroaches as the new fourth pest

In addition to the "elimination of the four evils" that constantly wins, but never wants to completely win. The greatest achievement of the health campaign in the past few years should be the control of many "endemic diseases", among which nutritional diseases such as "big neck disease" and insufficient micronutrient intake or "spotted tooth" have begun to disappear rapidly with the efforts of Wu Xian, Zheng Ji and other nutrition experts and the broad masses of cadres and masses, especially the production and promotion of iodized salt and other nutritionally fortified foods are of great significance.

And. Because of the reminder of Hu Weidong, the promotion of iodized salt in this time and space has been treated separately, and the sales of non-iodized salt are much looser than those in history, and ordinary stores can also sell it, not limited to county and city salt companies, and there is no longer a need for a doctor's prescription for corresponding diseases such as hyperthyroidism when purchasing. In this way, it is much easier to conduct chemical experiments and when certain diseases need it. As for the problem of some people coveting cheap salt and not eating iodized salt, it is enough to set the price of non-iodized salt slightly more expensive than iodized salt, but what Hu Weidong does not understand is that the price of non-iodized salt has been set at a higher price than iodized salt in later generations, so why should the sales of non-iodized salt be strictly controlled on the grounds of "worrying that some people are greedy for cheap and do not eat iodized salt"?

In addition, parasitic diseases, which are more difficult to solve, have also been generally controlled, which has completely failed the thesis of many foreign experts that "it cannot be effectively controlled within ten years".

One of the most influential is schistosomiasis (to be precise, it should be Japanese schistosomiasis, and the other schistosomiasis are much less harmful). In the "extermination of snails" campaign launched by Taizu and the masses, most of the main epidemic areas of schistosomiasis in the country have been controlled. As in history, after receiving the good news, Taizu happily wrote the poem "Seven Laws. Send the Plague God" to express their joy. However, Hu Weidong, who is well aware of the lessons of history, poured cold water on it at this time, and he wrote an article sharply pointing out that the threat of schistosomiasis has not been completely eradicated, and that it cannot be relaxed until the snail is completely eradicated (Japan has done it in history, and the key is to persist and not relax halfway). Considering the national character of the Chinese, perseverance may indeed be difficult, but it is absolutely impossible to say that it is not possible. Eventually, after nearly half a century of unremitting efforts (Note 1) in southern China, the species was finally wiped out in China, thus completely eliminating this huge threat to people's health.

However, Hu Weidong also took into account the economic cost, so after the mass movement to eradicate snails persisted for five whole years and the infection rate of schistosomiasis was reduced to less than 1 in 10,000, he proposed that the main work should be handed over to experts in biology and medicine, instead of always focusing on the extremely labor-intensive mass prevention and control, so as not to occupy too much labor for a long time and affect economic development, even if there is a surplus of manpower, it should be used for more important matters such as predicting earthquakes.

Note 1: The Japanese also spent almost half a century in history, their territory is relatively small, and the difficulty of exterminating snails is less than that of China, but they did not widely mobilize the masses, mainly the government and professionals are engaged in it, the speed is relatively slow, and we should be faster when converted, and the campaign to exterminate snails in history in New China has had obvious results in just two years, but it is a pity that it was thought that there was no threat at the time and failed to continue to insist, until it re-spread decades later. At that time, it will be much more difficult to extinguish it, and you must know that the artificiality of the 21st century is not comparable to that of the sixties and seventies (to be continued......