Identification of community flour mills as the source of lead poisoning in West Bank Arabs.

Following the discovery of severe lead poisoning in members of several households in a West Bank village, studies were carried out to establish the magnitude of the problem in the community and to identify the source of lead poisoning. Forty-three patients with Centers for Disease Control risk group IV lead poisoning were identified and treated in three villages within a radius of about 10 km of each other. The prevalence of increased lead burden among 563 schoolchildren aged 10 to 18 years was 19% for Centers for Disease Control risk groups I and II and 11% for groups III and IV. A survey of potential sources excluded all items, except for locally ground flour, which was heavily contaminated in all affected households. Examination of community flour mills revealed that, in contrast to unprocessed grain, freshly ground flour contained large amounts of lead originating from lead fillings employed to fasten the housing of the driveshafts to the millstones. Systematic screening of 146 community stone mills in 92 West Bank villages showed significant lead contamination of flour in 33 mills (23%). In all cases, the source of lead contamination was identical. As methods of milling in the area are similar, a prompt investigation of this potential source of lead poisoning in other near-Eastern countries is indicated.

Comparative content of total polyphenols and dietary fiber in tropical fruits and persimmon.

Recent studies have shown that dietary fiber and polyphenols of vegetables and fruits improve lipid metabolism and prevent the oxidation of low density lipoprotein cholesterol (LDL-C), which hinder the development of atherosclerosis. The goal of this study was to measure the total polyphenol and dietary fiber contents of some tropical fruits (i.e., pineapple, wax apple, rambutan, lichi, guava, and mango) and compare the results to the content of these substances in the better characterized persimmon. It was found that lichi, guava, and ripe mango (cv. Keaw) have 3.35, 4.95, and 6.25 mg of total polyphenols in 100 g fresh fruit, respectively. This is significantly higher than in persimmon, pineapple, wax apple, mature green mango, and rambutan [P < 0.0005 for pineapple (Smooth Cayene variant), wax apple, persimmon, rambutan, mature green mango (cv. Keaw); the value of P < 0.001 is found only for pineapple (Phuket, Queen variant)]. The same relationship was observed for the contents of gallic acid and of dietary fiber. It can be supposed that among the studied fruit, lichi, guava, and ripe mango may be preferable for dietary prevention of atherosclerosis.

Organochlorine insecticides and PCB residues in fat tissues of autopsied trauma victims in Israel: 1984 to 1986.

Between the 1950s and the 1970s, large quantities of organochlorines were used as insecticides in Israel's cowsheds, causing massive contamination of Israel's milk supply. In 32 of 40 autopsied Israeli trauma victims who died between 1984 to 1986, we found three or more types of organochlorines in adipose tissue, and at least one organochlorine residue in all 40 individuals. The cumulative mean organochlorine levels (ppm) in men and women were as follows: DDE = 5.73 and 4.36; DDT = 0.12 and 0.30; HCB = 0.31 and 0.11; beta-HCH = 0.53 and 0.43; PCB = 0.10 and 0.08, respectively. PCB residue levels in fat tissue were lower than those noted in other countries and below the adverse levels associated with health effects. The cumulative mean organochlorine levels in adipose tissue were higher in men than in women in all cases except for DDT. Mean levels for DDE + DDT combined was higher in older than younger people, and all persons' DDT/DDE ratios were less than 1. The DDE levels in adipose tissue were higher than the levels reported in many other countries during the 1970s, 1980s, and 1990s. Our findings suggest that population-wide exposures to organochlorine insecticides come not only from contaminated milk products but other food products as well. The amounts of organochlorines in adipose tissue are compatible with those found in food residue samples during the same period.

Lead poisoning by contaminated flour.

Between October 1982 and June 1983, 43 patients were identified with symptomatic lead poisoning in three Arab villages of the Nablus district. Because of the clustering of clinical poisoning by household units, investigation was focussed on potential sources common to all members of the households. After excluding water, olive oil and a variety of foodstuff, lead in high concentrations was discovered in locally ground flour in all affected households. The source of poisoning was lead poured into the fissures between the metal housing and the driveshaft of the millstone. Significant lead contamination of freshly ground flour was demonstrated in 23% of the 146 community flour mills operating in West Bank villages. Since the completion of these studies, similar outbreaks of lead poisoning caused by contaminated flourmills have been identified in the Upper Galilee and in Spain. As the methods of milling in the Mediterranean area are similar, a coordinated international effort is needed in order to eliminate this health hazard from countries where similar community stone mills are still in use.

Zinc protoporphyrin levels in children in Haifa: a pilot study.

Zinc protoporphyrin (ZPP) levels of greater than or equal to 40 micrograms dl-1 were found in blood samples of 32 (12.1%) out of 264 children living in Kiryat Yam, Haifa Bay (a sea-level neighborhood with much vehicular traffic, located 4.5 km from an industrial zone in the bay area), 22 (8.8%) out of 251 children living in Neve Shaanan (located on a mountainside, 3.5 km from an industrial zone and exposed to visible smoke pollution), and 14 (6.5%) out of 214 children from Mt Carmel (Ahuza), which is furthest from industry and where visible signs of pollution are seldom seen. Zinc protoporphyrin levels, low in non-anemic infants, were slightly higher in 1st graders from all three neighborhoods; higher levels were found in both 3rd and 6th graders from Kiryat Yam, but only in 6th graders from Neve Shaanan. The ZPP levels remained unchanged in older, Mt. Carmel children. Zinc protoporphyrin concentrations of greater than or equal to 40 micrograms dl-1 varied inversely with two indices of socio-economic status (parental ethnic origin and father's educational level). Blood lead levels of greater than or equal to 20 micrograms dl of blood were found in eight (13%) out of 62 children with ZPP levels greater than or equal to 40 micrograms dl-1, but in none (0%) of 14 children with ZPP levels greater than or equal to 40 micrograms dl-1. Three (60%) out of five children with ZPP levels greater than or equal to 50 micrograms dl-1 had Pb levels of greater than or equal to 20 micrograms dl-1. In Kiryat Yam, Pb(B) was higher in 31 children with ZPP greater than or equal to 40 micrograms dl-1 compared with 13 with ZPP less than 40 micrograms dl-1. The data on age-associated increases in ZPP in children suggest the possibility of an effect on red blood cell porphyrin metabolism, in some cases from cumulative low level lead exposures, and in others from iron deficiency, especially in poorer socio-economic groups. The findings call for further studies, both in the populations studied here, and elsewhere, to determine the role of lead toxicity and iron deficiency in children of all age groups, and the need for preventive action.

Re-emergence of lead poisoning from contaminated flour in a West Bank Palestinian village.

Although contaminated flour was first described as an important source of endemic lead poisoning in the Middle East almost 20 years ago, the use of lead in community flour mills has not been eliminated and continues to represent a significant environmental risk. The authors describe an outbreak of lead poisoning in a West Bank Palestinian family and draw attention to this unusual but important source of lead exposure. All 13 members of the family (two children and 11 adults), were found to have lead poisoning following hospitalization for "gastroenteritis," headache, joint pain, weight loss, and vision difficulties. Seven females had low hemoglobin levels. Blood lead concentrations ranged from 42 to 84 microg/dL. Household flour samples obtained from a stone mill, previously closed because of lead contamination, contained 2,000 ppm lead. Flour from traditional stone mills reinforced with lead joints remains a potential source for lead poisoning.

Illness and excretion of organophosphate metabolites four months after household pest extermination.

Diethyl phosphate (DEP), an organophosphate metabolite, was found in the urine of symptomatic residents who resided in a household that had been sprayed with diazinon 4.5 mo earlier. Pre- and post-decontamination data with regard to symptoms, DEP, cholinesterase, and surface and air levels underscore the utility of alkyl phosphate metabolites for monitoring exposure. The data also emphasize the efficacy of clean-up measures when baseline data are not available to determine if "within-normal" cholinesterase levels are, in fact, depressed.

Iron depletion and blood lead levels in a population with endemic lead poisoning.

The effect of iron depletion on blood lead levels was studied in a group of 558 schoolchildren aged 10 to 18 residing in two West Bank Arab villages with a high prevalence of excessive lead exposure and clinical lead poisoning. Thirty percent of the subjects studied had whole-blood lead levels greater than 30 micrograms/dl, and 45% had whole-blood zinc erythrocyte protoporphyrin greater than 50 micrograms/dl. The percentage of abnormal blood lead values in subjects with normal serum ferritin and transferrin saturation (31%) was similar to that in subjects with one (28%) or two (25%) abnormal iron parameters. Likewise, there was no correlation between serum ferritin and blood lead levels in individual patients (r = 0.059). Normal distribution plots and mean levels of blood lead (27.3 micrograms/dl) were identical in the iron-deficient and iron-replete groups. These findings indicate that iron depletion does not affect blood lead levels and suggest that in man, unlike in experimental animals, iron depletion may not have a significant effect on lead absorption.

Combined use of zinc protoporphyrin (ZPP), mean corpuscular volume and haemoglobin measurements for classifying microcytic RBC disorders in children and young adults.

The diagnostic potential of the combined use of zinc-protoporphyrin (ZPP), mean corpuscular volume (MCV) and haemoglobin measurements for discriminating between iron deficiency anaemia, beta-thalassaemia minor and lead poisoning has been studied. Lead poisoning could be identified by ZPP greater than 50 micrograms/dl in the presence of normal MCV or ZPP greater than 150 micrograms/dl in the presence of microcytosis (MCV less than 80 fl) with a sensitivity of 97% and specificity 94%. Beta-thalassaemia minor was identified by the coexistence of microcytosis and ZPP less than 50 micrograms/dl with a sensitivity of 91% and specificity 79%. Iron deficiency anaemia defined by the combination of microcytosis and ZPP ranging from 50 to 150 micrograms/dl was identified with a sensitivity of 95%, but the specificity was only 51%, with many of the patients overlapping with thalassaemia minor. This problem did not exist in iron-deficiency anaemia with haemoglobin less than 10 g/dl as at that range no patients with uncomplicated thalassaemia minor have been encountered. A great advantage of the combined use of ZPP, MCV and haemoglobin for the initial screening of microcytic anaemia is its ease of performance and low cost. However, this information should only be regarded as presumptive evidence of disease, requiring subsequent confirmation by appropriate direct measurements such as transferrin saturation, serum ferritin, haemoglobin electrophoresis, or blood lead determinations.

Mercury levels among dental personnel in Israel: a preliminary study.

Amalgam, the most prevalent dental restoration material used in dentistry, is potentially toxic because it contains mercury. Recent international publications confirm that mercury is potentially hazardous to dental personnel, who are exposed to mercury vapors both during their work at the office and from amalgam restorations in their own oral cavities. The purpose of our study was to compare urinary mercury levels of dental personnel with a control group, and to explore possible correlations between environmental factors in the dental office and the urinary level of the personnel. Our results indicate that the urinary mercury levels of the tested dental professionals were significantly higher than those of the control group (2.39 +/- 0.319 vs. 0.899 +/- 0.34 micrograms mercury/g creatinine). Of the dental personnel examined, 72% had detectable levels of urinary mercury, compared to 27% of the control group. Although mercury levels in all participants did not exceed the toxic limit, the above findings clearly point to the need for a continuation of this survey.

Health effects from exposure to organophosphate pesticides in workers and residents in Israel.

Major findings from our work on exposures and effects from organophosphate-containing pesticides in selected occupational and community patients and groups in Israel are reviewed as a basis for recommending control measures. The worker groups were pilots, ground-crews, and field workers; exposed nonworkers were adults and children living in kibbutzim with drift exposures, and household residents in houses treated by pest exterminators. In all groups, evidence of exposure-illness associations was found even though persons with acute poisoning were not seen. Complaints (headache, dizziness, fatigue, nausea, breathing problems, abdominal cramps, and tingling in extremities) were associated with within-normal depressions in cholinesterase activity. Whole blood and plasma cholinesterase activity were slightly more sensitive indicators of mixed exposure than red blood cell cholinesterase activity. High alkyl phosphate levels and symptoms were seen in individuals with within-normal limit depressions in cholinesterase activity. Complaints of weakness and tingling in hands and feet, together with low-grade changes in nerve conduction, suggest the possible influence of agents with a neurotoxic esterase-type activity independent of cholinesterase activity. Transient in-season neuropsychological changes in tests of mood status and performance were associated with exposure. Recommendations for exposure reduction include: accelerating the already declining use of pesticides in general, and organophosphates in particular; promoting the shift from more to less toxic organophosphates and other pesticides; and introducing rigid performance specifications for closed systems in loading and mixing at end-user sites. Dermal protection remains a problem. Cholinesterase activity levels and symptom interviews are useful for monitoring workers at risk, but alkyl phosphate levels are the definitive measure of exposure, surveys, investigations and surveillance.