Air Quality of Work, Residential, and Traffic Areas during the COVID-19 Lockdown with Insights to Improve Air Quality

This study investigated the concentrations of air pollutants (NO, NO2, NOx, SO2, CO, O3, PM10, and PM2.5) at three sites with different traffic loads (work, residential, and traffic sites) before, during, and after the COVID-19 lockdown. The main objective of this study was to evaluate the effects and associated potential pollution control implications of the lockdown on the quality of ambient air at three selected sites in the urban area of Riyadh City. The average concentrations of NO, NO2, NOx, and CO decreased during the lockdown period by 73%, 44%, 53%, and 32% at the work site; 222%, 85%, 100%, and 60% at the residential site; and 133%, 60%, 101%, and 103% at the traffic site relative to the pre-lockdown period, respectively. The average concentration of O3 increased by 6% at the work site, whereas the concentration of SO2 increased by 27% at the residential site and decreased by 6.5% at the work site. The changes in PM10 and PM2.5 varied and did not exhibit a clear pattern. The air quality index (AQI) results indicated that the contribution to “undesired” air quality by O3 was 35.29% of the lockdown period at the work site while contributions to undesired air quality by PM10 and PM2.5 were 75.6% and 100% at the work site, 94.5% and 100% at the residential site, and 96.7% and 100% at the traffic site, respectively. The findings of this study are useful for devising effective urban pollution abatement policies. Applying control measures comparable to the lockdown measures over one week will result in a decrease of approximately 19% and 15% in CO mean concentration and 25% and 18% in NO2 mean concentration at residential and traffic sites, respectively.

Concentration, Distribution, and Potential Sources of Heavy Metals in Households Dust in Al-Fallujah, Iraq

Household dust pollution with heavy metals attracted the attention of researchers and environmental managers due to the risk of the health of these metals. The study aims are to determine heavy metals concentrations (Cd, Cr, Cu, Ni, Pb, Zn), their spatial distribution, and their potential sources in the household dust of Al-Fallujah City, Iraq. The dust was sampled from 50 houses. The heavy metals levels in the dust were measured using the atomic absorption spectrophotometry method. The mean concentration of heavy metal was ordered as following: Zn (292.85 mg/kg) > Cr (289.45 mg/kg) > Ni (105.72 mg/kg) > Pb (75.57 mg/kg) > Cu (65.03 mg/kg) > Cd (14.77 mg/kg). The mean concentration of these metals exceeded the reference values. The areal distribution of the reported heavy metals showed specific and non-specific patterns indicating point and non-point pollution sources. The heavy metals potential sources in house dust in the study area were characterized using correlation, Principle components and cluster analyses. The potential sources for Cd, Cu and Pb were interior and exterior sources, while the Ni and Cr were derived from internal sources. This study provides the environmental protection managers and decision-makers with important information about heavy metals concentrations and their sources in indoor environments.

Assessment of Cadmium Toxicity in Drinking Water of Eight Talukas of Upper Sindh

In the present study, 240 groundwater samples were collected from eight Talukas of upper Sindh. The cadmium (Cd) content was determined by atomic absorption spectrophotometer. Concentration (µg/L), Daily Intake ofMetals (DIM),Health Risk Indexes (HRI) for children and adults caused due to Cd were measured through equations of EPA and WHO. Mean concentration of Cd in different Talukas of upper Sindh was found as; Daharki (6.20 µg/L), Ubauro (7.73 µg/L), Kashmore (7.53 µg/L), Tangwani (7.73 µg/L), Garhi Khairo (6.20 µg/L), Thul (5.00 µg/L), Qambar (7.674 µg/L) and Miro Khan (7.47 µg/L). Moreover, percent contamination of each Taluka was found as, Daharki (80%), Ubauro (93%), Kashmore (93%), Tangwani (93%), Gharhi Khairo (70%), Thul (56%), Qambar (93%) and Miro Khan (93%). The DIM of Cd for adult and children was calculated the range for adults was found as; Daharki (0.00006 - 0.00036), Ubauro (0.00006 - 0.00042), Kashmore (0.00006 - 0.00036), Tangwani (0.00006 - 0.00042), Garhi Khairo (0.00003 - 0.00056), Thul (0.00003 - 0.00056), Qambar (0.00008 - 0.00039) and Miro Khan (0.00008 - 0.00039) mg/kg-d, whereas, for children DIM of Cd was found lower than adults. The HRI values show that children compared to adults are under the potential risk threat due to HRI values > 1. Therefore, it can be suggested that groundwater found in above stated areas is unsafe for drinking purposes and must be treated before consumption.

Occurrence, Levels and Spatial Distribution of Polybrominated Diphenyl Ethers: Case Study of Elemi River in Ado-Ekiti, Nigeria

Polybrominated diphenyl ethers (PBDEs) were seasonally determined in water and sediments of the Elemi River, Nigeria using gas chromatography analysis. Samples were collected in two consecutive seasons for six months, monitoring the program every month. Three BDEs congeners (28, 47 and 154) were only detected with the mean concentration of ND - 0.001 µg/L and ND - 0.143 µg/kg in water and sediments, respectively. BDEs (99, 100, 153, 183 and 209) were consistently absent in both seasons. The distribution of BDEs showed that BDE 28 was consistently found in the water samples throughout the months of sampling, while the sediments sparingly contained BDE 28 and 47. The study proposed the need for effective measures to reduce the deleterious contribution of these persistent compounds into the rivers.

Antibody-mediated Immunogenicity against SARS-CoV-2 following priming, boosting and hybrid immunity: insights from 11 months of follow-up of a healthcare worker cohort in Israel, December 2020-October 2021

Background: We determined circulating anti-S SARS-CoV-2 IgG antibody titres in a vaccinated healthcare workers (HCWs) cohort from Northern Israel in the 11 months following primary vaccination according to age, ethnicity, boosting timing and previous infection status. Methods: All consenting HCWs were invited to have their circulating IgG levels measured before vaccination and at 6 subsequent timepoints. All HCWs with suspected COVID-19 were PCR tested. We described trends in circulating IgG geometric mean concentration by age, ethnicity, timing of boosting and previous infection status and compared strata using Kruskall-Wallis tests. Results: Among 985 vaccinated HCWs. IgG titres gradually decreased in all groups over the study duration. Younger or previously infected individuals had higher initial IgG levels (p<0.001 in both cases); differences substantially decreased or disappeared at 7-9 months, before boosting. Pre-infection IgG levels in infected participants were similar to levels measured at the same timepoint in HCWs who remained uninfected (p>0.3). IgG GMC in those boosted 6-7 months after dose 2 was lower compared with those boosted 8-9 months after (1999-vs 2736, p=0.02). Conclusions: Immunity waned 6 months post-priming in all age groups and in previously infected individuals, reversed by boosting. IgG titres decrease among previously infected individuals and the proportion of reinfected individuals in this group, comparable to the proportion of breakthrough infection in previously uninfected individuals suggests individuals with hybrid immunity (infection+vaccination) may also require further doses. Our study also highlights the difficulty in determining protective IgG levels and the need to clarify the optimal timing in 3 dose regimens

Human Biomonitoring of T-2 Toxin, T-2 Toxin-3-Glucoside and Their Metabolites in Urine through High-Resolution Mass Spectrometry

The metabolic profile of T-2 toxin (T-2) and its modified form T-2-3-glucoside (T-2-3-Glc) remain unexplored in human samples. Therefore, the present study aimed to investigate the presence of T-2, T-2-3-Glc and their respective major metabolites in human urine samples (n = 300) collected in South Italy through an ultra-high performance liquid chromatography (UHPLC) coupled to Q-Orbitrap-HRMS methodology. T-2 was quantified in 21% of samples at a mean concentration of 1.34 ng/mg Crea (range: 0.22–6.54 ng/mg Crea). Almost all the major T-2 metabolites previously characterized in vitro were tentatively found, remarking the occurrence of 3′-OH-T-2 (99.7%), T-2 triol (56%) and HT-2 (30%). Regarding T-2-3-Glc, a low prevalence of the parent mycotoxin (1%) and its metabolites were observed, with HT-2-3-Glc (17%) being the most prevalent compound, although hydroxylated products were also detected. Attending to the large number of testing positive for T-2 or its metabolites, this study found a frequent exposure in Italian population.

Evaluation of human exposure to parabens in north eastern Poland through hair sample analysis

Parabens (PBs) are a group of substances commonly used in industry. They also pollute the environment, penetrate into living organisms and adversely affect various internal organs. During this study, the degree of exposure of people living in Olsztyn, a city in north eastern Poland, to selected parabens most often used in industry was studied. The chemicals under investigation included: methyl paraben—MePB, ethyl paraben—EtPB, propyl paraben—PrPB, benzyl paraben BePB and butyl paraben -BuPB. To this aim, hair samples collected from the scalps of 30 volunteers were analyzed using a liquid chromatography–mass spectrometry technique. All PBs studied were present in a high percentage of analyzed samples (from 76.7% in the case of BePB to 100% in the case of MePB and PrPB). The mean concentration levels were 4425.3 pg/mg for MeBP, 704.0 pg/mg for EtPB, 825.7 pg/mg for PrPB, 135.2 pg/mg for BePB and 154.5 pg/mg for BuPB. Significant differences in PB concentration levels between particular persons were visible. On the other hand, gender, age and artificial hair coloring did not cause statistically significant differences in PB levels. Obtained results have clearly indicated that people living in north eastern Poland are exposed to various PBs, and therefore these substances may affect their health status. However, the evaluation of PBs influence on human health requires further research.

Heavy metal contamination and antibiotic residues in poultry feed and meat in Bangladesh

Presence of harmful contaminants and residues in poultry feed and meat have serious public health consequence. This study was carried out to identify and quantify antibiotic residues, heavy metals and toxins in poultry feed and meat in the two selected poultry production belts of Bangladesh. A total of 94 broiler feed samples and 60 broiler meat samples were collected and tested by Thin Layer Chromatography (TLC), High Performance Liquid Chromatography (HPLC) and Enzyme-linked Immunosorbent Assay (ELISA) for identification and quantification of the parameters. Antibiotic residues were detected in 18.89% of the feed samples, whereas, there were no toxin (Aflatoxin) positive samples. Among the antibiotic positive samples, Oxytetracycline (OTC) was found predominant and detected in 12.22% cases. The mean concentrations of Cadmium (Cd), Lead (Pb), Chromium (Cr) were found as 0.04 mg/kg, 1.28 mg/kg and 2.55 mg/kg respectively in feed samples. In the case of meat samples, the mean concentration of OTC, Ciprofloxacin (CIP), and Tetracycline (TCL) residues were found 8.67 ppb, 7.18 ppb and 0.81 ppb accordingly. The highest mean concentration of Oxytetracycline (OTC) (10.15 ppb) was found in samples collected from local poultry sellers, whereas, the highest mean concentration of Tetracycline (TCL) (1.35 ppb) and Ciprofloxacin (CIP) (10.62 ppb) were observed in the samples obtained from local farm. The highest percentage of TCL and CIP (64% and 48% respectively) were found in samples collected from local farm. Chlortetracycline (CTC) was found predominant (70%) in samples collected from Contract farms. On the other hand, out of 60 meat samples, Cd and Cr were detected in only one meat sample with concentration of 56.41 mg/kg and 14.44 mg/kg respectively. Lead was not detected in any of the meat samples. Asian Australas. J. Food Saf. Secur. 2021, 5 (2), 71-78

Assessment of significant metals in effluents, soil, and pond water of tanneries south of capital of Sudan state

In the present study, impact of tannery effluents and their subsequent on accumulation of some metals (Ca, K, Na, Mg, Cl, S, Cr, Fe, Mn, Pb, and Zn) in water and soil samples in and around South Khartoum industrial area, Khartoum-Sudan were studied. Concentration of metals in tannery effluents (SA), adjacent contaminated pond water (SB), Soil (SC), and uncontaminated water (SD) were assessed by atomic absorption photometer. The results showed high levels of Ca, K, Na, Mg, Cl, S, Cr, Fe, Mn, Pb, and Zn within the water from all sampling point (SA, SB and SC). The investigation exhibited that tanneries wastewater has high mean concentrations of Cr, Fe, Mn, and Pb in all sampling point of effluent, pond water, soil, and uncontaminated water, except Zn which is high only in soil sampling point (SC). The significant metals accumulation displayed a pattern of mean concentration as follow: Soil > Effluent >contaminated pond water > Un contaminated water. Significant metals toxicity levels within the totally different sampling points were compared with water from WHO. Mean metal concentrations in un contaminated water were among the allowable limit set by WHO except for Magnesium (Mg). The comparison indicated that soil (SC) within the neighboring industrial area accumulated metals, enhanced levels of toxic of metals such as Cr, Ni, Zn and Pb, which also demonstrated higher concentration levels in the adjacent contaminated pond water samples. increased levels of poisonous, that additionally incontestable higher concentration levels within the contaminated pond water.