Increased inflammation in rheumatoid arthritis patients living where farm soils contain high levels of copper.

Abstract

Heavy metal pollution in farm soils is a problem in some parts of Taiwan. Copper can be a factor associated with increased disease activities of rheumatoid arthritis (RA). Thus, the aim of this study was to investigate whether copper pollution in farm soils is associated with worsened RA. Clinical parameters from 122 RA patients were collected from a medical center in central Taiwan. Levels of heavy metals in the blood were measured using inductively coupled plasma mass spectrometry. Levels of copper in farm soils were retrieved from a national survey. These data were analyzed to find the factors related to RA disease activities. RA patients living where farm soils contained high levels of copper had increased white blood cell counts, erythrocyte sedimentation rate, and disease activity score 28, compared with patients living where copper levels were low. Among the nine types of heavy metal measured in the study, blood levels of copper and nickel correlated with erythrocyte sedimentation rate. Our cross-sectional data suggest a correlation between RA disease activity and the level of copper at township farm soils samples. Further longitudinal studies using more rigorous methodologies are warranted to examine whether this correlation is causal.