1, potential danger
Like biotechnology, nanotechnology also has many environmental and safety problems (such as whether small size will avoid the natural defense system of organisms, whether it can be biodegradable, how toxic and side effects are, and so on). ).
2, the harm of nanoparticles
The existence of nanomaterials (materials containing nanoparticles) is not a hazard in itself. Only some aspects are harmful, especially their mobility and enhanced responsiveness. Only when some aspects of some nanoparticles are harmful to organisms or the environment can we face real harm.
In order to discuss the impact of nanomaterials on health and environment, we must distinguish between two types of nanostructures:
Nano-composite materials, nano-surface structures or nano-elements (electronic and optical sensors, etc.). ) assembled with nano-sized particles on a substrate, and materials or devices are also called fixed nanoparticles.
"Free" nanoparticles, whether individual nanoparticles are stored or directly used in some production steps.
These free nanoparticles can be nano-sized single elements, compounds or complex mixtures, such as "coated" nanoparticles or "core-shell" nanoparticles with one element coated with another substance.
It is generally accepted that although we need to pay attention to materials with fixed nanoparticles, free nanoparticles are the most urgent concern.
Because nanoparticles are so different from nanoparticles in daily life, their harmful effects cannot be inferred from the known toxicity. It is of great significance to discuss the effects of free nanoparticles on health and environment in this way.
health problem
There are four ways for nanoparticles to enter the human body: inhalation, swallowing, skin absorption or intentional injection (or release from implants) during medical treatment. Once in the human body, they are highly mobile. In some cases, they can even cross the blood-brain barrier.
The behavior of nanoparticles in organs is still a big topic to be studied. Basically, the behavior of nanoparticles depends on their size, shape and interaction with surrounding tissues. They may lead to "overload" of phagocytes (cells that devour and destroy foreign substances), thus causing defensive fever and reducing the body's immunity.
They may accumulate in organs because they cannot degrade or degrade slowly. Another worry is their potential danger of reacting with some biological processes in the human body. Due to the huge surface area, nanoparticles exposed to tissues and liquids will immediately adsorb the macromolecules they encounter. For example, this will affect the regulation mechanism of enzymes and other protein.
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