Blood lead concentration in children after gunshot injuries.

Blood lead and erythrocyte zinc protoporphyrin values were examined in 23 children who had suffered gunshot (including multiple shotgun) injuries. No child had any evidence of lead poisoning between 15 and 27 months after the injury despite, in some cases, the retention of multiple pellets. Reference to previous publications suggests that lead poisoning is an unlikely complication of gunshot injury, providing a bullet or pellet is not retained in contact with a synovial cavity.

Free erythrocyte protoporphyrin levels in the first year of life.

Free erythrocyte protoporphyrin (FEP) levels were measured in 161 infants judged not to be iron-deficient. In addition to high mean FEP levels in cord blood, a significant number of infants had FEP levels in excess of 120 micrograms/dl red blood cells during the first 6 months of life. These levels are comparable to those found in iron-deficient adults. It is concluded that the clinical significance of an FEP level in excess of 120 micrograms/dl and its value as a marker of early iron deficiency during the first 6 months of life require further study. FEP values in excess of 120 micrograms/dl were not observed in infants aged 7-12 months.

Reference concentrations of serum selenium and manganese in healthy nulliparas.

Reference serum selenium and manganese concentrations were established for healthy nulliparas aged 18-23 years resident in Cape Town. Measurements were determined for selenium in 100 female students who had been taking low-dosage triphasic contraceptive medication for a minimum of 3 months and in 100 female students who were not on contraceptive therapy. Manganese concentrations were determined for 25 female students from each group. The mean serum selenium concentrations were 0.988 +/- 0.189 micrograms/l (78 +/- 15 micrograms/dl) and 0.925 +/- 0.177 mumol/l (73 +/- 14 micrograms/l) respectively for females taking and not taking oral contraceptives. The corresponding concentrations for manganese were 21.84 +/- 9.82 nmol/l (1.20 +/- 0.54 micrograms/l) and 21.66 +/- 7.64 nmol/l (1.19 +/- 0.42 micrograms/l) respectively. The differences in selenium were statistically significant (P = 0.0231) but not for manganese (P = 0.910).

Serum zinc and copper levels in children with meningococcal disease.

Mean serum zinc and copper levels were depressed in 94 children aged 1 month to 9 years who presented with meningococcal disease. The mean serum zinc level was 44 micrograms/dl (reference value 78 micrograms/dl, SD 18) and the mean serum copper level 157 micrograms/dl (reference value 159 micrograms/dl, SD 27). Nineteen patients had serum zinc levels less than 25 micrograms/dl and ten patients had serum copper levels less than 101 micrograms/dl. Serum zinc levels were significantly lower in patients who were septicaemic or in whom manifestations of severe disease such as shock, more than 20 petechiae, ecchymoses and evidence of disseminated intravascular coagulation occurred compared to those without these features. Serum copper concentrations were higher than reference levels in patients with meningitis and in less severely ill patients. Copper levels were significantly lower in patients with septicaemia, severe disease, shock, more than 20 petechiae, ecchymoses, disseminated intravascular coagulation, leucopenia and patients who died compared with patients without these features.

Ferritin levels in human milk.

Ferritin was detected and quantitated in breast milk from 24 mothers of healthy fullterm infants 3 days, 7 days, 6 weeks and 3 months after delivery. Highest concentrations were found at day 3 and demonstrated a marked decline at day 7, with negligible levels at 6 weeks and 3 months. The values in breast milk were compared with mother's serum ferritin concentration at delivery and a significant but weak correlation (r = 0.475, P less than 0.05) was found between the paired values of maternal serum ferritin at delivery and breast milk ferritin at day 3. The possible biological significance of ferritin in breast milk is discussed.

Blood lead levels in young newspaper vendors.

Young newspaper vendors spend long hours working in high-traffic areas and may be at risk of lead toxicity. Two groups of these vendors working in areas with different atmospheric lead levels were compared with a control group. Vendors in central Cape Town (mean ambient lead level of 2.1 mg/m3) had a mean blood lead level of 19.5 micrograms/dl, whereas vendors in Bellville (mean ambient lead level of 0.65 mg/m3) had a mean blood lead level of 15.4 micrograms/dl. The mean blood lead level of the control group was 11.0 micrograms/dl. These differences were statistically significant and lend support to the view that direct absorption of atmospheric lead can make a considerable contribution to lead load.

Reference values for serum copper, ceruloplasmin and zinc and haematological indices for healthy nulliparous females.

Reference serum copper, ceruloplasmin and zinc values were established for 100 healthy white nulliparous students aged 18-23 years resident in Cape Town who had been taking low-dosage triphasic contraceptives for a minimum period of 3 months, and in 100 female students not taking contraceptives. The mean serum copper values were 26.5 +/- 4.2 mumol/l and 16.9 +/- 2.7 mumol/l for those taking and not taking oral contraceptives respectively; corresponding values for ceruloplasmin were 181 +/- 43.9 IU/ml and 110 +/- 22.7 IU/ml respectively. Both differences were statistically significant. Serum zinc values for those on contraceptives were 14.1 +/- 2.1 mumol/l and for the others 14.7 +/- 2.0 mumol/l. There were no differences in the haematological parameters except for a significantly higher mean corpuscular volume in females taking oral contraceptives. Of possible clinical significance in this student population are prevalence rates of 2.2% for anaemia (haemoglobin value less than 11.5 g/dl), 7% for iron deficiency (serum ferritin less than 12 micrograms/l) and 6.6% for iron depletion (serum ferritin 12-20 micrograms/l).

Blood lead levels in preschool children in Cape Town.

Blood lead levels were assessed in 293 children aged between 4 and 6 years attending preschool centres in metropolitan Cape Town in order to establish the degree of lead absorption. Anthropometric data, blood count, zinc protoporphyrin and blood lead level were obtained for each child. A questionnaire was used to determine socio-economic status, dietary habits and history of pica. Thirteen children, or 4,4% of those sampled, had blood levels of greater than or equal to 30 micrograms/dl. The majority of these children lived in close proximity to one another in a socially deprived inner urban environment. Environmental sampling for lead was carried out in the homes of children with the highest blood levels as well as in the homes of a matched control group with low levels living in the same area. The only difference was a significantly higher incidence of pica in the children with high levels.

Lead absorption in Cape children: a preliminary report.

There is little information on environmental lead absorption in childhood in southern Africa. The concentration of lead in the dentine of shed teeth was measured as a cumulative marker of long-term absorption in 80 children attending a Cape Town dental clinic. Blood lead levels were determined in 226 children, 114 from the Red Cross War Memorial Children's Hospital, Cape Town, 23 from Ciskei and 89 from a dental clinic. This small survey reports on the precision of laboratory technique and indicates that some children living in urban Cape Town have accumulated lead to an extent comparable to that in large Western cities.

Measurement of zinc and copper levels in breast milk.

Zinc and copper levels in breast milk were measured to assess the accuracy of the analysis and to obtain a range of values for the local population. Samples were collected 7 days after delivery from 48 well-nourished mothers who had given birth to healthy full-term infants. The method was found to be accurate and reproducible provided precautionary measures were taken to avoid sample contamination. A wide variation in values was found in samples from different mothers, however, ranging from 155 to 680 microgram/dl for zinc and from 27 to 90 microgram/dl for copper.

Serum zinc and copper levels in the 1st year of life.

Zinc and copper concentrations in the serum of 240 healthy infants aged 1-12 months were measured by the atomic absorption spectrophotometric method. The study was designed so that on completion there would be 20 infants in each of 12 groups according to age by month. The mean serum zinc levels remained fairly constant in all the age groups except for a significant fall from levels at 1 month (77,11 +/- 12,85 micrograms/dl) to those at 2 months of age (66,60 +/- 15,18 micrograms/dl) (P less than 0,025). Another significant decline in serum zinc levels was present between 4 and 5 months of age (P less than 0,05), which was followed by a significant increase between 5 and 6 months of age (P less than 0,05). The infants' mean serum zinc levels were lower than those of normal adults at all ages (P less than 0,05). The mean serum copper levels were low at 1 month of age (71,17 +/- 17,30 micrograms/dl), and increased significantly between 1 and 2 months (P less than 0,001) and 3 and 4 months of age (P less than 0,02). Mean serum copper levels similar to those of adults were reached at 4 months of age. These levels remained fairly constant from 5 months of age onwards, the only significant decline being noted at between 7 and 8 months of age (P less than 0,05). The present study substantiates previous findings that a specific pattern of change in serum copper concentrations which differs from the trend in serum zinc levels occurs in infants after birth. To detect zinc and copper depletion it is important to interpret serum concentrations in relation to normal values for age.

Zinc and copper levels in the breast-milk of Cape Town mothers.

Zinc and copper levels were measured longitudinally in the breast-milk of 55 healthy South African women from the middle and upper socio-economic classes. The mean foremilk zinc levels showed a significant fall (P less than 0,05) from 652,9 +/- 240,7 micrograms/dl at 3 days after delivery to 413,3 +/- 143,0 micrograms/dl at 7 days and 228,1 +/- 136,1 micrograms/dl at 6 weeks. Lower foremilk zinc levels were obtained at 36 weeks (64,3 +/- 50,0 micrograms/dl). In contrast, foremilk copper levels were low at 3 days (57,0 +/- 74,8 micrograms/dl), with a gradual decline to very low levels (28,0 +/- 29,7 micrograms/dl) at 36 weeks. No differences were detected between the fore- and hindmilk zinc and copper levels at any stage of lactation studied (P greater than 0,05).

Serum zinc and copper levels in healthy middle and higher socio-economic class infants in Cape Town. A longitudinal study during the 1st year of life.

Serum zinc and copper levels were measured using a flame atomic absorption technique in 55 healthy infants and their middle and upper socio-economic class mothers at delivery, and also longitudinally in the infants during the first 12 months of life. Mean cord serum zinc levels (99.50 +/- 27.63 micrograms/100 ml) were 1.5 times higher than maternal serum levels at birth (66.3 +/- 21.0 micrograms/100 ml). The mean serum zinc levels showed no significant change (P greater than 0.05) at each of the study periods. However, the mean serum zinc levels at birth were significantly higher (P less than 0.05), than those after 6 weeks. The infants' levels remained within the normal adult range at all the study periods. The mean cord serum copper levels (34.46 +/- 12.60 micrograms/100 ml) were about one-sixth of the mean maternal serum copper levels at delivery (217.7 +/- 64.39 micrograms/100 ml). The mean serum copper levels increased significantly (P less than 0.05) from birth to 12 months of age. Mean serum copper levels similar to those of normal adults were reached at 12-24 weeks.

Serum zinc and copper levels in healthy South African women at term and during the first year after childbirth.

Serum zinc and copper levels were measured longitudinally in 55 healthy middle and upper socio-economic group white mothers living in Cape Town from the birth of the baby to 12 months after parturition. Mean maternal serum zinc levels showed a significant rise (P less than 0.05) from delivery (66.34 +/- 21.07 micrograms/100 ml) to 12 weeks (87.88 +/- 15.93 micrograms/100 ml), but no further changes were detected at 24, 36 and 52 weeks after parturition. The mean maternal serum copper levels decreased from 217.73 +/- 64.34 micrograms/100 ml at delivery to 141.65 +/- 45.60 micrograms/100 ml at 12 weeks (P less than 0.05); they remained constant at all the other sampling periods. No differences (P greater than 0.05) were noted at all the different sampling periods between mean serum zinc levels of primiparous and multiparous mothers, but mean serum copper levels were significantly higher (P less than 0.05) in the primiparas. The mean serum zinc and copper levels of healthy white South African mothers at delivery and 12 months after parturition correspond with those for Northern American mothers. Normal non-pregnant adult serum zinc and copper levels were attained within 12 weeks of delivery.