Evaluation of blood lead among painters of buildings and cars

Determination of mercury, cadmium, and nickel in henna samples

In most countries around the world, henna (Lawsonia inermis) has been widely used for centuries as a traditional cosmetic and therapeutic plant. However, there is a growing concern about the safety and potential toxicity associated with the use of henna. The research aimed to analyze the levels of mercury (Hg), cadmium (Cd), and nickel (Ni) in 36 henna samples (red, green, black) from both locally produced and imported products commonly used in Iran. The henna samples analysis was carried out using an atomic absorption spectrometry (AAS) system. The level of Hg in all samples was lower than 0.002 µg/g. The levels of Cd and Ni in the samples were at the ranges of 0.25 - 2.05 µg/g (mean = 0.85 µg/g) and 6.7 - 21.8 µg/g (mean = 14.35 µg/g), respectively. The level of Cd in 94.5% of samples was higher than the maximum permissible limits (0.3 µg/g) recommended by the World Health Organization (WHO). To our knowledge, this paper is the first investigation into the level of Hg, Cd, and Ni in Iran's henna. The findings from this study showed that levels of Cd and Ni in henna samples used in Iran were high and seemed to pose a threat to health.

Toxic metal contamination in edible salts and its attributed human health risks: a systematic review and meta-analysis

Sodium chloride, commonly referred to as table salt, is the most widely utilized seasoning in culinary applications. Nevertheless, the most of oral salts used contain impurities. Arsenic (As), mercury (Hg), cadmium (Cd), and lead (Pb) are the most common impurities found in salt. In this meta-analysis, we examined the status of Pb, Hg, Cd, and As in the salt sample consumed in Iran. For this purpose, a complete search was carried out in English (Scopus, PubMed, and Web of Science) and Persian (Scientific Information Database, IranMedex, and Magiran) electronic databases to identify related articles published by July 2024. In the present meta-analysis, twelve studies with a total number of 610 salt samples were included in the analyses. According to the findings, the pooled mean levels of Hg, Pb, As, and Cd were 0.06 µg/g (95% CI: 0.04-0.08), 2.98 µg/g (95% CI: 2.35-3.61), 0.42 µg/g (95% CI: 0.19-0.66), and 0.71 µg/g (95% CI: 0.76-1.04), respectively. The levels of Cd and Pb in rock salt are higher than those found in the sea and refined salt. The hazard index (HI) values were recorded as 0.41 (95% CI: 0.235 to 0.588) for men, 0.428 (95% CI: 0.246 to 0.614) for women, and 0.594 (95% CI: 0.341 to 0.853) for children. The results of the present study show higher levels of Pb and Cd in unrefined salt compared to refined salt. Additionally, the health risk associated with exposure to Cd, Pb, As, and Hg through salt consumption is negligible in Iranian adults.

Assessment of occupational exposure to lead among workers engaged in a city bus garage in Addis Ababa, Ethiopia: a comparative cross-sectional study

BACKGROUND

Lead is one of the most nonessential toxic heavy metal agents found in automotive garages. The occupational exposure of garage workers to lead commonly poses acute and chronic health risks that can be prevented. In Ethiopia, there have been limited studies on lead exposure among garage workers, who overemphasize exposure to lead. This study aimed to assess occupational blood lead levels and associated factors in garage workers using a cross-sectional comparative design.

METHODS

A comparative cross-sectional study design was used to compare the occupational blood lead levels of 36 randomly selected garage workers and 34 office workers who were matched by age and sex. Blood specimens were collected by trained medical laboratory experts. The collected blood samples were tested in a certified laboratory using a microwave plasma atomic emission spectrometry (MP-AES) device at a wavelength of 405.78 nm. Excel and SPSS Version 26 were used for data management and analysis, respectively.

RESULTS

The mean (SD) age of the exposed group was 39.0 (7.5) years, whereas the mean age of the unexposed group was 38.0 (6.1) years. The occupational mean (SD) blood-lead-level in the exposed groups was 29.7 (12.2) µg/dl, compared to 14.8 (9.9) µg/dl among the unexposed groups. The mean blood-lead level among the exposed workers was significantly different from that among the unexposed workers (P < 0.01). Of all the study participants, only 22.2% of the exposed groups had blood lead levels higher than the World Health Organization's recommended limit of 40 µg/dl. The main significant predictors of occupational blood-lead-level exposure among workers were extra working hours, service years, and having a previous (prior) employment history in a garage. The occupations of the two groups did not significantly differ in terms of blood-lead levels (p > 0.05).

CONCLUSIONS

The BLL of the Garage workers was significantly greater than that of the Non-Garage workers. Hence, it is advised that garage management should encourage workers to use exposure prevention methods, such as washing their hands before eating and taking showers after the completion of work, by providing regular occupational safety training.

Involvement of Nrf2 Signaling in Lead-induced Toxicity

Nuclear factor erythroid 2-related factor 2 (Nrf2) is used as one of the main protective factors against various pathological processes, as it regulates cells resistant to oxidation. Several studies have extensively explored the relationship between environmental exposure to heavy metals, particularly lead (Pb), and the development of various human diseases. These metals have been reported to be able to, directly and indirectly, induce the production of reactive oxygen species (ROS) and cause oxidative stress in various organs. Since Nrf2 signaling is important in maintaining redox status, it has a dual role depending on the specific biological context. On the one hand, Nrf2 provides a protective mechanism against metal-induced toxicity; on the other hand, it can induce metalinduced carcinogenesis upon prolonged exposure and activation. Therefore, the aim of this review was to summarize the latest knowledge on the functional interrelation between toxic metals, such as Pb and Nrf2 signaling.

Contamination of breast milk with lead, mercury, arsenic, and cadmium in Iran: a systematic review and meta-analysis

Breast milk is a complete food for the development of the newborn, but it can also be an important route for environmental pollutants transmission to the infants. This study was aimed to evaluate the status of heavy metals including lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As) in the breast milk of Iranian mothers. The international databases including Scopus, PubMed, Web of Science and the Persian electronic databases including Scientific Information Database, IranMedex and Magiran were examined to find relevant articles published until July 2021. A total of 23 studies examined the levels of toxic metals in Iranian breast milk samples. According to the findings, the pooled average concentrations (µg/L) of Pb, Cd, Hg and As were 25.61, 2.40, 1.29 and 1.16, respectively. The concentration of Hg and Pb in colostrum milk was more than twice of mature milk. The Hg mean concentration in the breast milk of mothers with at least one amalgam-filled tooth was approximately three times that of mothers without amalgam-filled teeth. Risk assessment analysis indicated that the intake of Pb and Hg by infants through breastfeeding can be considered a health concern in Iran. It seems necessary to reduce the Pb exposure of pregnant and lactating women in Iran. However, more extensive studies are needed to clarify the toxic metals' exposure status of infants through breast milk in other parts of the country.