A 45-year-old woman who had suffered from gastrointestinal (GI) symptoms similar to irritable bowel disease since adolescence sought a private practitioner in 1991 when she suspected medical problems from amalgam dental fillings. In addition to the bowel symptoms, she suffered from fatigue. An analysis of the metal content in the patient’s feces showed considerably increased concentrations of mercury, cadmium, and lead. In 1992 she was referred to the Department of Occupational and Environmental Medicine of Huddinge Hospital, Stockholm, Sweden, for further investigation. No source of occupational or environmental metal exposure was identified, and the patient showed blood concentrations of mercury and cadmium within normal ranges. The patient’s blood lead concentration was 100 μg/L. The reference level used by the analytical laboratory at that time was < 145 μg/L. The analysis of metals in feces is considered much more unreliable than levels in blood, and the physician concluded that there was no evidence of environmental exposure to lead, mercury, or cadmium. Chelation therapy with dimercaptosuccinic acid (DMSA), which had been initiated by the practitioner in 1991, was continued for 2 years. The patient received oral treatment two to three times per week, but we do not know the exact dose. Symptoms were mainly unchanged during the treatment period.
In August 2001 when the patient saw another physician, a moderately increased blood lead level of 210 μg/L was found (normal range in unexposed subjects < 40 μg/L). At that time, the DMSA medication was started again, and she was referred to the Department of Occupational and Environmental Health in Stockholm. A repeated blood lead sample in December 2001 showed an even higher blood lead concentration of 550 μg/L.
This patient was born in Germany in 1956 and moved to Sweden in the mid-1970s. During 1980-1994 she gave birth to eight children, the last of them twins. In the early 1980s she worked at day care centers, and in 1997 she began working part-time cleaning buildings. The family lived in a house built in the 1930s. She was a smoker during the 1980s (except during pregnancy), but she quit smoking in the early 1990s. Her alcohol consumption was low, about one bottle of wine per month, and she did not abuse drugs. She had no psychiatric problems.
During the investigation at the Department of Occupational and Environmental Health she reported increasing GI problems with daily diarrhea for about a year. She also suffered from coldlike symptoms in combination with malaise and fatigue several times a week. A clinical examination, including a standard neurologic examination (standard arm and leg reflexes, skin sensibility, and two-point discrimination in hands) was normal.
Figure 1 shows the development of the patient’s blood lead pattern. Blood lead levels peaked in December 2001, and thereafter a gradual decline was evident. Beginning in December 2001, all analyses were performed by inductively coupled plasma-mass spectrometry at laboratories that were accredited for analysis of lead in blood; previous samples (from August 2001 and 1991) were not analyzed at accredited laboratories. The DMSA treatment that had been started in 2001 was discontinued in February 2002.
In January 2002, we began our investigation by asking the patient about potential lead sources in her diet or in the environment. She had no contact with lead crystal glassware or lead-glazed pottery, and her food habits were normal. The blood lead concentrations in the other family members were normal. Her hematologic parameters and kidney function were normal, and she showed no signs of microproteinuria. In October 2002, lead in urine was increased (75 μg/L; reference value < 30 μg/L), and an X ray of the abdomen showed a dense rounded metal object with a diameter of approximately 6 mm at the colon ascendens. While waiting for a computed tomography (CT) scan, which we planned in order to localize the object more precisely, the patient contracted the winter vomiting disease (gastroenteritis) in January 2003. During severe diarrhea, the object was released from the GI tract. The object was identified as lead shot pellet used for game hunting, and marks on it showed that it had been fired through a rifle. The lead shot pellet had a diameter of 6 mm and a mass of 1.7 g (Figure 2). A new abdominal X ray confirmed that the object was no longer in the colon.
The woman confirmed that she had consumed game at several occasions: she had eaten wild boar at a restaurant in Sweden in 1993, and hare or rabbit on some occasions during the 1990s, both in Sweden and in Germany. However, she could not recall having eaten meat that contained a hard object at any time. Her blood lead levels in April 2003, 2 months after the elimination of the lead shot pellet from her colon, were still high (345 μg/L). After another 7 months, the patient’s blood lead concentration was 72 μg/L, almost down to reference levels. At that time, the attacks of malaise and fatigue had disappeared, and the abdominal symptoms were mild. Since 2003 she has been working full-time.
