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Let ũ denote the conjugate Poisson integral of a function $f\in L^p\left(ℝ\right)$. We give conditions on a region Ω so that $li{m}_{(v,\epsilon )\to (0,0)}(v,\epsilon )\in \Omega ũ(x+v,\epsilon )=Hf\left(x\right)$, the Hilbert transform of f at x, for a.e. x. We also consider more general Calderón-Zygmund singular integrals and give conditions on a set Ω so that $su{p}_{(v,r)\in \Omega }\left|{ʃ}_{\left|t\right|>r}k(x+v-t)f\left(t\right)dt\right|$ is a bounded operator on $L^p$, 1 < p < ∞, and is weak (1,1).