Which of the following is not an environmental risk factor for schizophrenia?

Environmental risk factor for schizophrenia - Environmental factors can predispose to the development of schizophrenia, precipitate the onset, provoke relapse after initial recovery, and maintain the disorder in persisting cases. Risk factor Relative risk ofdeveloping schizophrenia Predisposing Genetic Monozygotic twin of a schizophrenic patient 40 Dizygotic twin of a schizophrenic patient 15 Child of a schizophrenic patient 10-15 Sibling of a schizophrenic patient 10-15 Environmental Abnormalities of pregnancy and delivery 2 Maternal influenza (second trimester) 2 Migration 2 2 Winter bih 1.1 1.1 Precipitating Early cannabis consumption 2 Genes associated with schizophrenia Disc 1(disrupt in schizophrenia) COMT (catechol o methyl transferese) NRG 1 (neuregulin) GRM 3 (glutamate receptor metabotropic) RGS -4 (regulator of g protein signaling) DAOA (d amino acid oxidase activator)