  A study of the spin 1 Unruh-De Witt detectors interacting with a relativistic
scalar quantum field is presented. After tracing out the field modes, the
resulting density matrix for a bipartite qutrit system is employed to
investigate the violation of the Bell-CHSH inequality. Unlike the case of spin
$1/2$, for which the effects of the quantum field result in a decreasing of the
size of violation, in the case of spin $1$ both decreasing and increasing of
the violation may occur. This effect is ascribed to the fact that Tsirelson's
bound is not saturated in the case of qutrits.
