Objective-To critically review the literature on male reproductive toxicity of lead in animals and humans. Methods-A systematic literature search identified a total of 32 experimental studies in animals and 22 epidemiological studies, one case report on humans and five review articles or documents. The studies were evaluated by paying attention mainly to sample size, study design, exposure, and dose characterisation, analytical method standardisation, and quality assurance. Results-Several studies on rats and other rodents indicated that blood lead concentrations >30-40 µg/dl were associated with impairment of spermatogenesis and reduced concentrations of androgens. However, other animal studies, mainly about histopathological, spermatozoal, and hormonal end points, indicated that certain species and strains were quite resistant to the reproductive toxicity of lead and that diVerent testicular lead concentrations could account for these diVerences. The human studies focused mainly on semen quality, endocrine function, and birth rates in occupationally exposed subjects, and showed that exposure to concentrations of inorganic lead >40 µg/dl in blood impaired male reproductive function by reducing sperm count, volume, and density, or changing sperm motility and morphology. No relevant eVects were detected on endocrine profile. Conclusion-Several factors make it diYcult to extrapolate the animal data to the human situation. The diYculties are mainly due to diVerences between species in reproductive end points and to the level of exposure. Concentrations of blood lead >40 µg/dl seemed to be associated with a decrease in sperm count, volume, motility, and morphological alterations and a possible modest eVect on endocrine profile. Dose-response relation, in particular at a threshold level, is poorly understood, and site, mode, or mechanism of action are unknown. Also, the eVects were not always the same or associated in the same way, although the prevalent eVects were on sperm count and concentration. Some methodological issues and indications for future studies are discussed. (Occup Environ Med 1998;55:364-374)

SummaryOBJECTIVES OBJECTIVES To describe the neurolathyrism epidemic in Ethiopia and to identify associated household factors. METHODS METHODSWe interviewed 589 randomly selected heads of household in Debre Sina district of Ethiopia, the area af¯icted by the recent neurolathyrism epidemic. Disease information was obtained for 2987 family members. RESULTS RESULTSNeurolathyrism patients were detected in 56 (9.5%) households (prevalence rate 2.38%). The mean number of affected family members per household was 1.27 (SD 0.65, range 1±3). Most (77.5%) patients developed the disability during the epidemic (1995±1999). The median age at onset of paralysis was 11 years with a range of 41 (range 3±44). Younger people were more affected during the epidemic than during the non-epidemic period (P 0.01). The presence of a neurolathyrism patient in the family was associated with illiteracy [adjusted OR (95% CI) 2.23 (1.07±5.10)] of the head of household, with owning a grass pea farm [adjusted OR (95% CI) 2.01 (1.04±3.88)] and with the exclusive cooking of grass pea foods using handmade traditional clay pots [adjusted OR (95% CI 2.06 (1.08±3.90)].CONCLUSIO N CONCLUSION Males aged 10±14 years were most affected by neurolathyrism. Increased household risk was associated with illiteracy of the head of the household and exclusive cooking of grass pea foods with handmade traditional clay pots.

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Summaryobjective To study an array of household individual and dietary risk factors for neurolathyrism. method Case-control study using recent cases in a district highly affected by the recent neurolathyrism epidemic in Ethiopia: 108 households with cases and 104 households with no cases; 170 neurolathyrism cases, 370 intra-family controls and 170 community controls frequency matched for age and sex.results A history of acute illness was associated with a two-and threefold increased risk of paralysis in community and intra-family controls, respectively. Soaking grass pea in water before cooking roughly halved the risk of neurolathyrism but cooking in clay utensils more than quadrupled it. Consumption of grass pea in the green unripe and boiled forms increased the risk 10 times or more. Mixing the food with gravy that contains condiments with antioxidant activity reduced it by a factor of 4. The consumption of grass pea mixed with cereals rich in sulphur amino acids was also highly protective, but the magnitude of the effect depended on the grass pea preparation consumed.conclusion Consumption of pure grass pea, especially in the green unripe and boiled forms, should be avoided. Communities at risk of neurolathyrism during famine crises should be encouraged to combine and use grass pea with cereals before the household cereal stock is fully depleted. Breeding programmes, alongside traditional attempts to reduce the toxin content, should enhance the content of sulphur amino acids and antioxidants in grass pea.

Only few studies have assessed relative risks on occupational asthma and allergy among bakery workers, and none of them have included respiratory and work-related symptoms as well as sensitization to occupational allergens and pulmonary function. A random sample of 246 workers from traditional and industrial bakeries in two regions of Belgium were compared with a reference population of 251 workers from a petrochemical plant in the same region. Data on skin test positivity, symptoms, and lung function were collected by standardized procedures. Differences between the two subpopulations were analyzed using multiple logistic and linear regression analyses. On average, bakery workers did not more often have skin test positivity than reference workers (39.4% and 42.6%, respectively). However, bakery workers had a strongly increased risk of sensitization to specific bakery allergens (OR 22.0, 95% CI = 6.3-77.1.), whereas their risks of positive skin tests to common allergens, including wheat pollen and storage mite, were significantly decreased (OR 0.6, 95% CI = 0.4-0.9). Bakery workers had significantly more often respiratory and work-related symptoms. Accordingly, they had lower lung function parameters. Atopy and sensitization to bakers' allergens were independent and additional risk factors for work-related symptoms. Bakery workers are at increased risk of respiratory and allergic symptoms and skin test reactivity to specific bakers' allergens wheat flour and alpha-amylase. Wheat pollen and storage mite should not be regarded as baker's allergens. Nevertheless, pulmonary function of bakery workers can be characterized as mild airway obstruction only.