Environmental assessment of pediatric Lead exposure in Tehran; a prospective cross-sectional study

Modulation of Kynurenic Acid Production by N-acetylcysteine Prevents Cognitive Impairment in Adulthood Induced by Lead Exposure during Lactation in Mice

Lead (Pb2+) exposure during early life induces cognitive impairment, which was recently associated with an increase in brain kynurenic acid (KYNA), an antagonist of NMDA and alpha-7 nicotinic receptors. It has been described that N-acetylcysteine (NAC) favors an antioxidant environment and inhibits kynurenine aminotransferase II activity (KAT II, the main enzyme of KYNA production), leading to brain KYNA levels decrease and cognitive improvement. This study aimed to investigate whether the NAC modulation of the brain KYNA levels in mice ameliorated Pb2+-induced cognitive impairment. The dams were divided into four groups: Control, Pb2+, NAC, and Pb2++NAC, which were given drinking water or 500 ppm lead acetate in the drinking water ad libitum, from 0 to 23 postnatal days (PNDs). The NAC and Pb2++NAC groups were simultaneously fed NAC (350 mg/day) in their chow from 0 to 23 PNDs. At PND 60, the effect of the treatment with Pb2+ and in combination with NAC on learning and memory performance was evaluated. Immediately after behavioral evaluation, brain tissues were collected to assess the redox environment; KYNA and glutamate levels; and KAT II activity. The NAC treatment prevented the long-term memory deficit exhibited in the Pb2+ group. As expected, Pb2+ group showed redox environment alterations, fluctuations in glutamate levels, and an increase in KYNA levels, which were partially avoided by NAC co-administration. These results confirmed that the excessive KYNA levels induced by Pb2+ were involved in the onset of cognitive impairment and could be successfully prevented by NAC treatment. NAC could be a tool for testing in scenarios in which KYNA levels are associated with the induction of cognitive impairment.

Red fox as a potential bioindicator of metal contamination in a European environment

In times of widespread environmental pollution with heavy metals of anthropogenic origin and the increasing dynamics of this process, it is justified to collect as much data as possible on the concentration of metals in terrestial mammals from unpolluted areas. The purpose of this research was to present the concentration of essential (chromium, copper, iron, manganese, molybdenum, and zinc), probably essential (nickel, vanadium) and non-esential element (cadmium, lead, silver, strontium, and tin) in the liver, kidneys, muscles and brain of red fox (Vulpes vulpes) inhabiting north-western Poland. We revealed that the concentration of all metals, apart from Ni, was different between studied tissues. Sn and Mo have the highest affinity to the liver, whereas Ag, Sr, Cr had higher concentrations in the brain than in other organs. Various positive relationship between the concentrations of metals were observed in the tissues. Moreover, we noted negative correlations between Ag and Sn in the kidneys and brain, and between Cu and Ag in the liver. In our study the red fox was used as biomonitor for the assessment of exposure of carnivores to metals, in the generally unpolluted areas of Central Europe. Data presented in the report may be used as comparative values in similar ecotoxicological studies.

Blood lead level evaluation in children presenting with chronic constipation in Tehran-Iran: a cross-sectional study

Constipation is a common reason for children seeking medical care worldwide. Abdominal complaints and constipation are also common in lead-poisoned children. This study evaluates the prevalence of abnormal blood lead levels (BLL) among pediatric and adolescent patients and examines the association of constipation with elevated BLL. This was a prospective data collection of patients younger than 18 years old with the chief complaint of constipation seen in the Mofid Children's Hospital gastroenterology clinic and Loghman Hakim pediatric and pediatric gastroenterology clinics were eligible for enrollment in this study. Constipation was defined as infrequent or difficult defecation according to ROME IV criteria lasting 2 months or more. BLL was measured with a fresh capillary whole blood capillary sample. The LeadCare II device assays BLL using an electrochemical technique (anodic stripping voltammetry). A total of 237 patients were enrolled in the study. 122 (51.48%) were female and 115 (48.52%) were male. About one fifth of patients (49; 20.67%) had BLL ≥ 5 µg/dL. The mean BLL in the sample was 3.51 µg/dL. Abdominal pain was the most common symptom accompanying constipation (134; 56%). Multivariate analysis found endoscopic evaluation (P values 0.024, OR 3.646, 95% CI 1.189-11.178), muscle pain (P values 0.020, OR 24.74, 95% CI 1.67-365.83), and maternal education (P values 0.02, OR 4.45, 95% CI 1.27-15.57) with significant differences in groups of patients with normal and elevated BLL. Elevated BLL necessitates an assessment and plans to reduce childhood lead exposure. BLL screening in childhood constipation with refractory chronic abdominal pain may also eradicate the need for invasive procedures like endoscopic evaluation.

Potential Health Risks of Lead Exposure from Early Life through Later Life: Implications for Public Health Education

Lead (Pb) exposure has been a serious environmental and public health problem throughout the world over the years. The major sources of lead in the past were paint and gasoline before they were phased out due to its toxicity. Meanwhile, people continue to be exposed to lead from time to time through many other sources such as water, food, soil and air. Lead exposure from these sources could have detrimental effects on human health, especially in children. UNICEF reported that approximately 800 million children have blood lead levels (BLLs) at or above 5 micrograms per deciliter (µg/dL) globally. This paper reports on the potential risks of lead exposure from early life through later life. The articles used in this study were searched from databases such as Springer, Science Direct, Hindawi, MDPI, Google Scholar, PubMed and other academic databases. The levels of lead exposure in low income and middle-income countries (LMICs) and high-income countries (HICs) were reported, with the former being more affected. The intake of certain nutrients could play an essential role in reducing (e.g., calcium and iron) or increasing (e.g., high fat foods) lead absorption in children. Elevated blood lead levels may disturb the cells' biological metabolism by replacing beneficial ions in the body such as calcium, magnesium, iron and sodium. Once these ions are replaced by lead, they can lead to brain disorders, resulting in reduced IQ, learning difficulties, reduced attention span and some behavioral problems. Exposure to lead at an early age may lead to the development of more critical problems later in life. This is because exposure to this metal can be harmful even at low exposure levels and may have a lasting and irreversible effect on humans. Precautionary measures should be put in place to prevent future exposure. These will go a long way in safeguarding the health of everyone, most especially the young ones.