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.