79.        This newspaper editorial concludes that our city should build a plant for burning
trash in order to avoid the serious health threats associated with many landfills. The
author adds that an incinerator could offer economic benefits as well, since incinerators
can be adapted to generate small amounts of electricity for other uses, and since ash
residue¹ from some kinds of trash can be used as a soil conditioner. Even if these claims
are true, the author's argument is unconvincing in three important respects.
      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 outweigh² 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.
      Secondly³, the author assumes that discontinuing landfill operations would abate⁴
the heath threats they now pose. However, this is not necessarily the case. It is possible
that irreversible environmental damage to subterranean⁵ 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 implicit⁶ claim that incinerators are economically
advantageous⁷ 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 inadequate⁸ justification⁹ 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 cost-benefit 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

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