Are there risks in taking 180 mg EPA plus 120 mg DHA daily? How long before it may be effective?

The average intake of EPA plus DHA in the average North American adult is 130 mg/day. The dietitians of North America have recommended an intake of 500 mg/day for health while the American Heart Association have suggested 900-1000 mg/day for those with coronary heart disease. When the daily oral intake of EPA/DHA is increased, it takes about 21 days for the blood levels to approach reaching the new higher level.