LONDON (Reuters) - Oil prices fell $1 on Monday to a six-week low as concern that inflation may slow economic growth encouraged selling across commodities markets. U.S. crude was trading 98 cents lower at $67.55 a barrel at 0819 GMT after falling more than $1 to its lowest level since April 10. Brent crude was down 84 cents at $67.85. The drop added to a slide of nearly 5 percent last week after signs that the record cost of many raw materials was pushing up the cost of living and hitting consumers' pockets. Rising inflation may force central banks to...