Sewage analysis as an alternative tool for assessing drug of abuse and new psychoactive substances in Tunisia.

Many studies attest to the pollution of wastewaters by organic molecules including drug of abuse (DAs) residues and new psychoactive substances (NPS) at trace levels. The occurrence of these emerging micropollutants in influent wastewaters (IWW) from three Tunisian Wastewater Treatment Plants (WWTPs) was assessed. Influent wastewater composite samples (24 h) were collected over 7 consecutive days in November 2019. The determination and quantification of 11 drug of abuse or their metabolites was performed by the application of an optimized multi-residue method liquid chromatography tandem mass spectrometry (LC-MS/MS). MDMA, THC and the cocaine metabolite benzoyl ecgonine were the most detected substances across the three investigated sewage plants. A new wastewater-based epidemiology (WBE) approach was applied in this study to estimate illicit drug consumption. This innovative approach was used to calculate and to assess collective drug consumption of illicit drug at a community level, based on the concentration of selected illicit substances and their major metabolites in influent wastewater. The average MDMA consumption found in the selected cities ranged between 35,8-1531,1 mg day- 1/1000 inhabitants and increased during the weekends. Cocaine consumption varied from 24.5 to 179.8 mg day- 1/1000 inhabitants. Complementary qualitative investigation of new psychoactive substances was monitored for the first time for an African country, examining the occurrence of 33 NPS in wastewaters samples. Out of 33 totals screened NPS across all sampling sites, 16 were tentatively identified with this approach. The 16 detected NPS covered most of the representative and used molecules of different NPS classes; including synthetic opioids, synthetic cathinones, amphetamines derivatives and synthetic cannabinoids.

Effects of lead, cadmium, copper and zinc levels on the male reproductive function.

This study aimed to investigate the effects of heavy metals on measures of male fertility. One hundred and two infertile men with occupational exposure and thirty fertile men were included in this study. Blood and urinary levels of lead, cadmium, zinc and copper were measured by atomic absorption spectrophotometry. Semen parameters and a motile sperm organelle morphology examination were also performed. Measures of hormonal levels, oxidation-reduction potential, DNA fragmentation index and chromatin condensation were assessed for all participants. Heavy metals levels, oxidative stress and DNA quality were significantly higher in the infertile group compared to controls. FSH and testosterone levels were lower in the infertile group. A urinary cadmium level was positively associated with abnormal sperm morphology (r = .225, p < .05). Normal morphology was inversely correlated with the duration of the exposure (r = -.227, p = .022). The blood lead level was positively related to the level of testosterone (r = .223, p = .031). Cadmium and lead blood levels were positively correlated with the level of chromatin decondensation (r = .528, p < .001; r = .280, p = .017). Our study showed that occupational exposure to heavy metals is very harmful to reproductive health. DNA quality and oxidative stress investigations must be recommended for reprotoxic exposed patients prior to in vitro fertilisation treatment.

Development of metal hydroxide nanoparticles from eggshell waste and seawater and their application as flame retardants for ethylene-vinyl acetate copolymer (EVA).

Recently, calcium hydroxide and magnesium hydroxide nanoparticles have attracted a lot of research interest in different sectors: food, packaging, health, automotive construction and food application. In the present study, we report development of bio-material calcium hydroxide nanoparticles (Ceg-Ca(OH)2), obtained from chicken eggshell collected from the food industries as well as magnesium hydroxide nanoparticles obtained from seawater (Seaw-Mg(OH)2). The flame-retardant behavior of Ethylene-Vinyl Acetate copolymer (EVA) containing different blends of Ceg-Ca(OH)2 and Seaw-Mg(OH)2 nanoparticles has been evaluated using cone calorimeter. Our results showed the interest of combining both nanoparticles. In fact, the partial substitution of small Seaw-Mg(OH)2 content (10 wt%) by Ceg-Ca(OH)2 enables further reduction of pHRR from 251 to 206 kW/m2 without any reduction of the composite time to ignition (52 s). Furthermore, the partial substitution of 40 wt% Seaw-Mg(OH)2 nanoparticles by Ceg-Ca(OH)2 enables high flame retardant effect as well as the generation of cohesive residue.

Biomonitoring chronic lead exposure among battery manufacturing workers in Tunisia.

The aim of the study was the biomonitoring of the chronic exposure to Pb by measuring its levels in blood, urine, and hair of battery workers. Blood lead (BPb), urinary lead (UPb), hair lead (HPb), and urinary δ-aminolevulinic acid (UALA) levels were determined for 52 workers in a battery plant and compared to those of 20 non-occupational exposed subjects (controls). BPb and UPb levels were determined by graphite furnace atomic absorption spectrometry (GFAAS). HPb levels were measured by triple quadrupole ICP-MS and UALA levels were determined using cation exchanger column. The measured levels were significantly higher compared to the controls exceeding the OSHA cutoff values (p < 0.01). The GM mean levels of BPb, UPb, UALA, and HPb of workers were 715 µg L-1, 331 µg L-1, 16.3 mg g-1, and 234 µg g-1, respectively. The GM mean levels of BPb, UPb, UALA, and HPb of controls were 93.6 µg L-1, 36.3 µg L-1, 1.9 mg g-1, and 1.8 µg g-1, respectively. Significant correlations were observed between BPb and UALA (r = 0.630, p = 0.000), UPb and UALA (r = 0.566, p = 0.000), and between BPb and HPb (r = 0.466, p = 0.004). The significant correlation between BPb and HPb suggests the usefulness of hair for assessing occupational exposure particularly when the study area presents medium to high levels of Pb pollution. The association between Pb biomarkers and potential confounding factors revealed significant influence of the occupational factor over smoking and alcohol consumption. The results of this study urge for the reinforcement of the implemented engineering controls and safety measures in order to reduce exposure and to address the health issues related to Pb poisoning.

Evaluation of the status and the relationship between essential and toxic elements in the hair of occupationally exposed workers.

Lead poisoning is a common disease in lead-acid battery manufacturing industries. Workers can be also exposed to various toxic elements present as contaminants or used as catalysts to enhance batteries' performances. In the present study, levels of essential and toxic elements and their relationship were assessed by analyzing scalp hair samples of 52 workers in a Pb battery manufacturing plant. The impact of some confounding factors on hair mineral contents was also investigated. For comparative purposes, nonoccupationally exposed subjects were selected as controls. All elements were determined by triple quadrupole ICP-MS. The results indicated significantly higher levels of Pb, Sb, As, and Cd in the hair of workers when compared to controls (p < 0.01). The Spearman correlation test revealed significant correlations between Pb/Cr, Pb/Mn, Pb/Ni, Pb/As, Pb/Se, Pb/Sb, Hg/As, Hg/Sn, Hg/Sb, Sb/Cr, Sb/As, Sb/Se, Sb/Cd, Sb/Sn, Sn/Cr, Sn/As, Sn/Cd, Cd/As, Se/Ni, As/Cr, Ni/Cr, Ni/Mn, and Mn/Cr in the hair of workers and Pb/Cr, Pb/Mn, Pb/Ni, Pb/Cd, Mn/Ni, Mn/Cd, Cd/Ni, As/Ni, Sn/Ni, Sb/Sn, and Hg/Sn in the hair of controls. Multiple linear regression analysis revealed linear dependence including Cr = f(Pb, Ni, Sb), Mn = f(Ni, Sb), Ni = f(Mn, Cr, -Cd) (Cd was negatively correlated, ß < 0), As = f(Sn, Sb, Hg), Se = f(Ni); Sn = f(As), Sb = f(As, Mn, -Hg, Sn, Se, -Ni) (Hg and Ni were negatively correlated), Hg = f(As, -Sb, Sn) (Sb was negatively correlated), and Pb = f(Cr). The result of this study can be very useful to explain the interactions between elements or for comparison studies when establishing reference ranges or monitoring elements in workplaces.

Health Risk Assessment of Heavy Metals in Traditional Cosmetics Sold in Tunisian Local Markets.

This study was undertaken in order to determine heavy metal contents in twelve (n = 12) henna brands and eleven (n = 11) kohl products. An analytical test was performed for Pb, Cd, Cu, and Zn in henna and kohl products using atomic absorption spectrophotometery. The overall mean concentrations of heavy metals in henna varied between 1.2 and 8.9 µg g(-1) for Pb; 0.8 and 18.6 µg g(-1) for Cd; 0.5 µg g(-1) and 3.3 µg g(-1) for Cu; and 3.7 µg g(-1) and 90.0 µg g(-1) for Zn. As for kohl products, Pb concentrations ranged between 51.1 µg g(-1) and 4839.5 µg g(-1), Cd concentrations ranged between 1.0 µg g(-1) and 158.6 µg g(-1), Cu concentrations ranged between 2.5 µg g(-1) and 162.5 µg g(-1), and Zn concentrations ranged between 0.7 µg g(-1) and 185.0 µg g(-1). The results of our study revealed that Pb, Cd, Cu, and Zn contents in investigated samples were high, making from the prolonged use of such products a potential threat to human health. Therefore, major quality controls are recommended in order to enforce acceptable limits of potential contaminants in cosmetics and good manufacturing practice.