To begin with, the author fails to consider health threats posed by incinerating trash. It is possible, for example, that respiratory problems resulting from the air pollution caused by burning trash might be so extensive that they would outweigh the health risks associated with landfills. If so, the author�s conclusion that switching to incineration would be more salutary for public health would be seriously undermined.

Secondly, the author assumes that discontinuing landfill operations would abate the heath threats they now pose. However, this is not necessarily the case. It is possible that irreversible environmental damage to subterranean water supplies, for example, has already occurred. In this event, changing from landfills to incinerators might not avoid or abate serious public health problems.

Thirdly, the author�s implicit claim that incinerators are economically advantageous to landfills is poorly supported. Only two small economic benefits of incineration are mentioned, while the costs associated with either burning trash or switching refuse disposal systems are ignored. In all likelihood, such costs would be significant, and may very well outweigh the economic benefits.

In conclusion, the author�s argument provides inadequate justification for switching from one disposal system to the other. As it stands, the argument takes into account only a limited number of benefits from the change, while addressing none of its costs. To better evaluate the argument, we must first examine all the health risks posed by each refuse disposal system and conduct a thorough costbenefit analysis of each system, taking account of the cost of the new system, the cost of the changeover itself, and the expected costs to the community of health problems resulting from each system.