Lead and cadmium in mangrove root crab (Goniopsis cruentata), in natura and at food processing stages

Assessment of potters' occupational exposure to lead and associated risk factors in Maragogipinho, Brazil: preliminary results

BACKGROUND AND PURPOSE

Lead (Pb) is used as a flux in the glazing process of pottery utensils in several regions of the world. It can affect the nervous and hematopoietic systems; in addition, it is classified as a probable human carcinogen. This work aims to evaluate Pb exposure of potters and describe the main determinants of elevated blood Pb (PbB) levels in this group of workers.

METHODS

This is a cross-sectional study with potters of Maragogipinho Village, Bahia, Brazil, of both sexes, aged 16-72 years (n = 85). Non-exposed workers of the same age range residing in the urban area of Aratuípe town were also recruited (n = 50). We evaluated Pb dust deposition rates (PbDrt) in pottery workshops and PbB levels. All Pb measurements were performed by Graphite Furnace Atomic Absorption Spectrometry.

RESULTS

The median of PbB (min-max) and geometric mean (SD) PbDrt for the exposed group were 7.9 (0.9-49.8) µg/dL and 1463 (± 290,000) μg/m²/30 days, respectively. For the control group, levels were 1.5 (0.1-19.8) μg/dL and 82 (46) μg/m² 30 days, respectively.

CONCLUSION

The data found showed an excessive exposure among artisans, exceeding occupationally safe levels and those reported in the literature. It is important to implement occupational hygiene measures and improvements of the working conditions of these labors, especially the replacement of lead oxide in the pottery-glazing process.

Zinc-protoporphyrin determination by HPLC with fluorescence detection as a biomarker of lead effect in artisanal pottery workers

Lead (Pb) exposure compromises heme synthesis by inhibiting ferrochelatase, forming zinc-protoporphyrin (ZnPP). This study aims to validate a method for the determination of ZnPP by HPLC with fluorescence detection and apply this method to evaluate the extent of Pb exposure of artisanal pottery workers. Extraction procedures were tested using both nonacid and acid liquid-liquid extraction. The former presented a better chromatogram and recovery results. The validated method yielded a good resolution of ZnPP and its free form peaks with acceptable precision and accuracy. Total run time was 15 min and ZnPP peak retention time was 5.6 min. We applied this method to evaluate 39 potters (90% male), mean age 40 years (9-80). The medians (ranges) of blood lead, ZnPP and hemoglobin were 16.0 μg/dl (2.2-71.5), 12.6 μg/dl (4.6-279.8) and 15.1 g/dl (11.0-17.8), respectively. Significant differences were observed for blood lead according to gender, age range (>40 years), direct handling of lead oxide and years of occupation. Significantly higher levels of ZnPP were observed in male potters involved with lead glazing activity. The validated method was shown to be simple with one-step nonacid extraction, good sensitivity, reproducibility and accuracy. Our data shows that these laborers are dangerously exposed to Pb, reflecting the effect on the heme synthesis.

Lead contamination in food consumed and produced in Brazil: Systematic review and meta-analysis

This systematic review (SR) evaluated evidence of lead (Pb) levels in foods consumed or produced in Brazil. Seventy-seven publications were included in this review, corresponding to a total of 8466 food samples that were grouped into 12 food categories with similar characteristics (infant food; sugar; beverages; meat and meat products; nuts, cocoa and products; fruits and fruit products; grains, cereals and products; milk and milk products; eggs; oil and fat spreads; vegetables and vegetable products and other foods). The random model was used to establish levels of Pb in food categories. We used the software R® to perform the meta-analysis. The overall occurrence of Pb was estimated at 0.0541 mg/kg, and ranged from 0.0004 mg/kg to 0.4842 mg/kg. The SR and meta-analysis presented relevant results about Pb contamination on foods, despite the high heterogeneity. They were understood as a viable strategy to answer questions regarding prevalence of Pb which is necessary for the risk assessment of Pb intake in foods.

Effects of chronic lead and cadmium exposure on the oriental river prawn (Macrobrachium nipponense) in laboratory conditions

During the past decade, the total population and overall reproductive performance of the oriental river prawn (Macrobrachium nipponense) in the Anzali international wetland and its basin rivers has been severely reduced. This seems to be caused by an increase in heavy metal pollution from industrial wastewaters. We investigated the effects of chronic levels of lead (Pb) and cadmium (Cd) on reproductive success, hemato-immunology, crustacean hyperglycemic hormone (cHH), Pb/Cd bioaccumulation and histopathology of hepatopancreas of oriental river prawn. The present study was separately carried out using four chronic treatments for Pb (0 (control), 0.024, 0.072 and 0.12 μM/l) and Cd (0 (control), 0.026, 0.053 and 0.08 μM/l) in experimental tanks during 60 days. The broodstock were fed by commercial shrimp diet, ad libitum, twice a day. The results revealed that reproductive activities ceased when Pb levels were 0.072 and 0.12 μM/l and also when Cd levels reached 0.08 μM/l. At 0.024 μM/l Pb, 0.026 and 0.053 μM/l Cd, the prawns showed initial reproductive activity but after spawning, the egg-clutches were found detached from the pleopods of the brood females. Hemato-immunology results showed that by increasing the Pb and Cd concentrations, large granular hemocyte (LGH) and cHH values also increased. However, small granular hemocyte (SGH) count was inversely affected. A significant increase in mortality (P < 0.05) was observed as both Pb and Cd concentrations increased. Histological observations are indicative of increased necrosis, lumen size, melanization, vacuolation and abnormal lumen shape, as the heavy metals concentrations increased. In conclusion, obtained results can help to elucidate effects of Pb and Cd on freshwater decapod crustaceans reproductive performance and related physiological parameters.

Lead in mangrove root crab (Goniopsis cruentata) and risk assessment due to exposure for estuarine villagers

This study evaluated lead (Pb) content in mangrove root crabs Goniopsis cruentata and performed a risk assessment based on individual frequency of food consumption of the residents of an estuarine village in Brazil. The Pb content in the raw and two forms of processed crabs were analyzed by graphite furnace atomic absorption spectrometry. Based on consumption by the community, estimates of non-carcinogenic target hazard quotients (THQ) were calculated. The mean (± SD) Pb concentrations in raw tissues were: 0.17 (± 0.36), < 0.012 and 0.05 (± 0.09) mg kg^-1 (gills, muscle and hepatopancreas), respectively. In the processed products, the highest levels were found in the traditional stew collected in April (2.84 mg kg^-1), surpassing the maximum limit allowed. The THQ for consumption of traditional stew was < 1, classified as negligible risk. The G. cruentata of the Jaguaripe River estuary can be considered a safe food, but cooking should be avoided in lead-glazed pottery.