Explain how fertilizers can also pose respiratory dangers

Although fertilizers are really helpful in maintaining the health and growth of crops or plants, because of its intrinsic chemical composition it can also be hazardous to a man's health. Respiratory disease associated with agriculture were one of the first recognized occupational hazards. Exposures to such may affect the airways that may result to asthma or asthma-like syndrome, and chronic obstructive pulmonary disease, which is practically dependent on the antigenecity or the ability to react with products of an immune response and host susceptibility. Inhalation of materials such  as fungal spores leads primarily to parenchymal dysfunction such as hypersensitivity pneumonitis.  Moldy hay, grain and similar organic materials has inherent endotoxins that may create a complex symptoms known as the ODTS or organic dust toxic syndrome which could represent a similar spectrum counterpart to hypersensitivity pneumonitis. 

When a virus infects a host cell, it uses the cell's machinery to make copies of its own genetic material in a process called replication. finally, during the process of self-assembly, that protein shell and the copies of the virus's genetic material are assembled into new viruses.