Haze weather caused by fine particles is even more harmful to human health than sandstorms. Particles with a particle size of more than 10 microns will be blocked out of the human nose; particles with a particle size between 2.5 and 10 microns, It can enter the upper respiratory tract, but part of it can be excreted through sputum, etc. , and it will also be blocked by the villi inside the nasal cavity, which is relatively less harmful to human health. Interfering with the gas exchange in the lungs, causing diseases including asthma, bronchitis, and cardiovascular disease. These particles also enter the blood, where harmful gases, heavy metals, etc. are dissolved in the blood, which is more harmful to human health. What does this text mean? ['Heavy metals will be dissolved in the blood and endanger human health.', 'Fine particles in haze weather are harmful to human health.', 'Different effects of particles with different particle sizes on human health.', 'The pathogenic mechanism of particles of different sizes in severe weather.']