Approximately three months after the initial accident Wetterhahn began experiencing brief episodes of abdominal discomfort and noted significant weight loss. The more distinctive neurological symptoms of mercury poisoning, including loss of balance and slurred speech, appeared in January 1997, five months after the accident. At this point, tests proved that she had a debilitating mercury intoxication. Her blood and urinary mercury content were measured at 4,000 µg L−1 and 234 µg L−1, respectively – both are well above their respective toxic thresholds of 200 µg L−1 and 50 µg L−1 (blood and urine reference ranges are 1 to 8 µg L−1 and 1 to 5 µg L−1).