Death and Serious Injury by Dark Matter
  Macroscopic dark matter refers to a variety of dark matter candidates that
would be expected to (elastically) scatter off of ordinary matter with a large
geometric cross-section. A wide range of macro masses $M_X$ and cross-sections
$\sigma_X$ remain unprobed. We show that over a wide region within the
unexplored parameter space, collisions of a macro with a human body would
result in serious injury or death. We use the absence of such unexplained
impacts with a well-monitored subset of the human population to exclude a
region bounded by $\sigma_X \geq 10^{-8} - 10^{-7}$ cm$^2$ and $M_X < 50$ kg.
Our results open a new window on dark matter: the human body as a dark matter
detector.
