Soybean peroxidase (SBP) has been employed for the treatment of aqueous solutions containing pentachlorophenol (PCP) in the presence of hydrogen peroxide at pH range 5–7. Reaction carried out with 1 mg/L of PCP, 4 mg/L of H₂O₂, and 1.3 × 10⁻⁹ M of SBP showed a fast initial elimination of PCP (ca. 30% in 20 min), but the reaction does not go beyond the removal of 50% of the initial concentration of PCP. Modification in SBP and PCP amounts did not change the reaction profile and higher amounts of H₂O₂ were detrimental for the reaction. Addition of Fe(II) to the system resulted in an acceleration of the process to reach nearly complete PCP removal at pH 5 or 6; this is more probably due to a synergetic effect of the enzymatic process and Fenton reaction. However, experiments developed in tap water resulted in a lower PCP elimination, but this inconvenience can be partly overcome by leaving the tap water overnight in an open vessel before reaction.

Background. The burden of chronic obstructive pulmonary disease (COPD) in India is not well understood. Due to geographical and environmental heterogeneity, the epidemiological profile of COPD may not be uniform across the country. Studies carried out in small geographical areas can help to determine the prevalence and risk factors of COPD. Objectives. The present study was conducted in one city in northwest India in order to calculate prevalence in small geographically determined areas within the city as well as across socio-economic strata and adjoining neighborhoods. Methods. The present study was conducted in Ludhiana, an industrial town in Punjab, India. Residential colonies were identified in an industrial and nonindustrial area and all households were screened for COPD using the Global Initiative for Chronic Obstructive Lung Disease criteria and confirmed by spirometry. Information about exposure to possible risk factors was also collected from suspected cases of COPD. Cases were mapped on a digital map of the city and hotspots were identified. Results. Fifty-six cases of COPD were detected. More than half (71%) were in the industrial area. The overall prevalence rate of COPD in the city was 3.17 per 1 000. The highest prevalence (5.6–9.4 per thousand) was observed in the colonies of the industrial area. All surveyed colonies in the nonindustrial area showed a low prevalence (0.0 to 0.9 per thousand). Conclusions. Hotspots were located in the industrial area and there was no such aggregation in the nonindustrial area. This suggests a potential association of industrial air pollutants with COPD. A strength of the present study is that it provides important baseline data. However, the study was limited, as it did not show a temporal association of exposure to air pollution and smoking with COPD. Participant Consent. Obtained Ethics Approval. The study was approved by the Institutional Ethics Committee for Human Research of the University College of Medical Sciences, Delhi, India. Informed Consent. Obtained Competing Interests. The authors declare no competing financial interests.

Background. Polycyclic aromatic hydrocarbons (PAHs) are toxic contaminants and pose health risks to humans and the ecosystem due to their persistence in the environment. Objectives. This study determined the concentrations of PAHs in sediment, two species of fish (Drepane africana and Pomadasys jubelini), crabs (Callinectes amnicola) and shrimps (Penaeus notialis) around the Atlas Cove jetty, Lagos, Nigeria. Methods. Polycyclic aromatic hydrocarbons were extracted from fish, shrimp, and crabs that were purchased from local fishermen. Sediments were collected at five locations impacted by ship movement and cargo offloading around the Atlas Cove jetty during the period of June to August 2016, using standard methods. Potential toxicity of PAHs in the sediments on the surrounding aquatic organisms was assessed. The PAHs were analyzed using gas chromatography-mass spectrometry. Human health risk assessment was calculated from biota using dietary daily intake and carcinogenic potencies of individual PAH concentrations. Results. A total of 17 PAH congeners were detected in sediment samples and ten were detected in biota samples. Concentrations of total PAHs obtained in sediment and fish samples ranged from 2.15 - 36.46 mg/kg and 11.89 - 71.06 mg/kg, respectively. The total PAHs concentration pattern follow the order of P. notialis > C. amnicola > P. jubelini (whole) > D. africana (whole) > D. africana (fillet) > P. jubelini (fillet) > sediment. Concentrations of total PAHs were higher in whole fish than in fillet samples (muscle) in both fish species. High values of PAHs were recorded in the dietary intake (0.10 - 2.33 mg/kg body weight/day) of the organisms. Toxic equivalent quotient values (0.01 to 0.10 mg/kg) were observed to be higher than the screening values (0.0014 to 0.0599 mg/kg). In the muscle of Drepane africana and Pomadasys jubelini, splitting and atrophy of the muscle bundles were observed. Conclusions. The concentrations of PAHs in analyzed sediment and organisms were higher than the maximum permissible limit of the United State Environmental Protection Agency (USEPA). Most of the detected PAHs were of petrogenic origin, which is an indication that anthropogenic activities were influencing PAH concentrations. Competing Interests. The authors declare no competing financial interests.

Background. The amalgamation method used by artisanal small-scale miners is the single largest source of global mercury emission. The goal of the ‘Free Your Mine’ project is to stop mercury use in artisanal and small-scale mining. Objectives. The aim of the present study was to compare gold recovery and time consumption between the amalgamation method and direct smelting, using borax for smelting under standardized conditions. Materials and Methods. This was an experimental study in a pragmatic setting in the mining community of Tiira, Uganda. Standardized amounts of gold ore of equal quality were processed with the local amalgamation method and with the Philippine mercury-free method as practiced by miners from Benguet in the Philippines, and the gold yield and time consumption were compared. Results. The amalgamation method took 53 minutes and recovered 1.0 g of pure gold. The miners used 4 g of mercury in the processing. The Philippine mercury-free method took 62 minutes and recovered 1.4 g of pure gold. Conclusions. The Philippine mercury-free method recovered 40% more gold than the amalgamation method but took 9 minutes longer. The Philippine mercury-free method is a viable alternative to amalgamation. Competing Interests. The authors declare no competing financial interests.

Background. Dust exposure and its related harmful effects on miners is a serious health issue. Objectives. The present study was undertaken to identify respirable dust concentrations and free silica content in 24 dust samples collected from a limestone mine during pre-monsoon and post-monsoon seasons. Methods. Time-weighted average (TWA) dust concentrations were calculated for 8-hour work shifts followed by determination of free silica concentration using the Fourier transform infrared spectroscopy technique. Results. The TWA dust concentration for personal and area dust samples during September 2013 was found to be in the range of 0.32–1.04 mg/m3 and 0.25–0.54 mg/m3, respectively. For February 2014, the TWA dust concentration was between 0.62–1.23 mg/m3 for personal samples and 1.04–2.64 mg/m3 for area samples. Samples collected in February 2014 had marginally higher values of dust levels in the air of the mine compared to September 2013. The highest dust concentration was found to be 1.23 mg/m3 for a drill operator and 2.64 mg/m3 at the crusher belt conveyor junction. The average free silica percent for the samples collected in February 2014 was 1.73%, which was almost double compared to September 2013 (0.87%). Conclusions. In both seasons, personal dust samples had higher free silica content than area dust samples. Even though dust concentrations were below the permissible limit, workers had widely different exposures, hence many of them may be at risk of pneumoconiosis when exposure is prolonged. Participant Consent. Obtained Competing Interests. The authors declare no competing financial interests.

Background. Chronic obstructive pulmonary disease (COPD) is an inflammatory disease with predominant involvement of neutrophils, macrophages and CD8+ lymphocytes. Eosinophilic airway inflammations are reported in stable state and during acute exacerbations of tobacco smoke-associated COPD (TS-COPD). Women exposed to biomass fuel smoke are known to have eosinophils in sputum. However, little is known about the sputum cellular inflammatory profile in biomass fuel smoke-associated COPD (BMS-COPD). We therefore aimed to compare the sputum cellular inflammatory profile in tobacco smoke- and biomass smoke-associated COPD. Methods. The study was conducted in a tertiary care hospital in Goa, India. A total of 113 patients with stable COPD reporting to the outpatient pulmonary clinic were recruited. All participants were ≥ 40 years of age. Sputum induction studies were performed by the method of Pizzichini et al. after baseline subject characterization. Significant eosinophilia was defined as induced sputum eosinophils ≥ 3%. Results. There were 85 TS-COPD and 28 BMS-COPD patients. The mean age [standard deviation (SD)] was 64.7 (7.8) and 63.0 years (8.3), p = 0.32 in TS and BMS-COPD, respectively. Eighteen subjects (21.1%) were female smokers. The smoking pack-year median [interquartile range (IQR)] was 36 (20, 58) and hour-years of biomass smoke exposure mean (SD) was 192.4 (61). The TS-COPD and BMS-COPD cases showed a post-bronchodilator forced expiratory volume in one second (FEV1%) mean (SD) of 57.9 (17.1), and 62.6 (19.4), p= 0.22, respectively. Both groups had similar symptoms and severity of disease. Induced sputum total cell count per gram of sputum × 106 mean (SD) was 3.05 (1.53) for TS-COPD, and 2.55(1.37) for BMS-COPD p=0.12. The neutrophils % mean (SD) was 86.4 (16.5) and 87.9 (10.2), p = 0.64; eosinophils % median (IQR) was 2.5 (1, 10) and 8 (2, 12.8), p = 0.07; lymphocytes % median (IQR) was 0 (0, 0.75) and 0 (0, 1) p = 0.13; macrophages % median (IQR) was 2.5 (0.75, 5.7) and 1 (0, 4.7) p = 0.13; and significant eosinophilia (eosinophils ≥3%) was 42 (49.4%) and 20 (71%), p=0.04, for TS-COPD and BMS-COPD, respectively. Conclusions. For similar severity of disease and clinical symptoms, significant eosinophilic inflammation was observed in stable BMS-COPD, while both groups had similar neutrophilic inflammation. Participant Consent. Obtained. Ethics Approval. The study was approved by the Institutional Ethics Committee of the Goa Medical College, Goa, India. Competing Interests. The authors declare no competing financial interests.

Background. Studies on environmental performance/quality and economic growth show inconclusive results. Objective. The aim of the present study is to assess the non-linear relationship between environmental performance and economic growth in the Middle East and North Africa (MENA) region from 2002–2018. Methods. A sample of fourteen (14) MENA countries was used in the present analysis. However, due to important differences between countries in this region, the whole sample was divided into two sub-samples; nine Middle Eastern countries (MEAS) and five North African countries (NAF). We performed the panel smooth transition regression model as an econometric approach. Discussion. Empirical results indicate a threshold effect in the environmental performance and economic growth relationship. The threshold value differs from one group of countries to another. More specifically, we found that the impact of environmental performance and economic growth is positive and significant only if a certain threshold level has been attained. Until then, the effect remains negative. Conclusions. The findings of the present study are of great importance for policymakers since they determine the optimal level of environmental performance required to act positively on the level of economic growth. MENA countries should seek to improve their environmental performance index in order to grow output. Competing Interests. The authors declare no competing financial interests.

Background. The primary environmental risk associated with artisanal small-scale gold mining (ASGM) activities in Sekotong and Taliwang is waste discharged directly into the environment. This waste contains variable concentrations of heavy metals and a high level of mercury. When these elements are released into the environment, plants and animals can be contaminated. If mercury is methylated to methylmercury, levels can increase in concentration at each level of the food chain (biomagnify). Fish are a primary risk vector for methylmercury poisoning in humans, and represent a significant source of protein for the Sekotong and Taliwang communities. Objectives. The present study aimed to identify the concentration of mercury in fish from ASGM sites in Sekotong and Taliwang. Methods. Descriptive research was used to describe the mercury concentrations of fish in the present study. The fish species collected for the samples represented commercially available fish most commonly consumed by the community on a daily basis. Results. In Sekotong's ASGM area, the mercury concentration in Pilsbryoconcha exilis tissue was 596 ppb, 721 ppb for Sephia officinalis and 50% of the Euthynnus affinis samples had a high level of mercury, above the World Health Organization (WHO) maximum permissable limit for the sale of fish for human consumption of 0.5 ppb. Conclusions. Some fish species from the studied ASGM sites had high mercury concentrations above the maximum permissible mercury concentration in edible fish tissue. The risks associated with mercury exposure from fish consumption threaten community health. Ethics Approval. All experiments were performed in accordance with relevant local guidelines and regulations. Competing Interests. The authors declare no competing financial interests.

Background. The use of strain-specific microbial fermentation in the production of organic acids for the removal of heavy metals from sludge has been extensively studied. However, there is scarce information on the use of microflora for fermentation. Objectives. To assess the efficacy of cassava peel extracts for the removal of heavy metals from hospital sewage sludge in Nigeria. Methods. A composite sewage sludge sample was collected from the University College Hospital sewage treatment plant in Ibadan, Nigeria and analyzed for heavy metals using standard methods. Aspergillus niger fermentation and crude fermentation extract were obtained from the cassava peels strain of Aspergillus niger and indigenous microflora, respectively. The experiment was carried out by adding 10 ml of the treatment to 3 g of each sludge sample (extracts and controls) at varied temperatures (room and elevated) and pH (3–5). The mixture was centrifuged after a contact time of 1–12 days at 1000 rpm for 1 hour. The filtrate was analyzed for heavy metals concentrations and compared with the standards. Data were analyzed using descriptive statistics and adsorption models. Results. Mean heavy metal concentrations in the sludge were estimated for copper (2.22±0.2 mg/kg), zinc (52.3±0.1 mg/kg), chromium (1.46±0.1 mg/kg), nickel (5.6±0.01 mg/kg), and lead (1.9±0.1 mg/kg) and were below permissible limits. Optimum heavy metal removal for Aspergillus niger fermentation extract at room temperature was achieved on day 12 at pH 3.5 for zinc (74.5%), while optimum heavy metal removal at elevated temperature was achieved on day 9 at pH 3.0 for lead (79.3%). The optimum pH for crude fermentation extract lies between pH 3.0–4.5 for nickel (76.2%) at room temperature and chromium (76.6%) at elevated temperature. Conclusions. Crude fermentation extract of cassava peel was found to be effective in removing heavy metals from sewage sludge. Therefore, its use could be adopted and promoted for removing heavy metals from sewage sludge to achieve safe disposal. Competing Interests. The authors declare no competing financial interests.

Background. Traffic-related air pollution (TRAP) is a major source of ambient air pollution in urban areas. Shopkeepers of heavily trafficked roadside shops are persistently exposed to high levels of TRAP. Objectives. To estimate the prevalence of respiratory morbidity in shopkeepers of shops in heavily trafficked roadside areas in Bhopal city (India) and to determine any association with long term exposure to TRAP. Methods. This cross-sectional study was conducted among 251 shopkeepers working in roadside shops of three major traffic corridors in Bhopal city. The demographic profile and prevalence of respiratory morbidity were collected by administering a validated questionnaire. The total exposure period (TEP) to TRAP was calculated for each individual by multiplying their work duration (in years) and average working hours per day. Odds ratios were calculated to estimate the association of TEP with respiratory morbidity. Results. The age of the study population was 44.8±13.5 years old and 95% were male. Nearly 55% of the shopkeepers reported at least one respiratory symptom. The prevalence of bronchial asthma, chronic bronchitis, breathlessness, and cough was 3.6% (95% confidence interval (CI): 1.9–6.7), 13.9% (95% CI: 10.2–18.8), 41.8% (95% CI: 35.9–48.0), and 18.3% (95% CI: 14.0–23.6), respectively. The adjusted risk ratios of bronchial asthma 2.17 (95% CI: 0.35–13.41), chronic bronchitis 1.42 (95% CI: 0.58–3.48), breathlessness 1.71 (95% CI: 0.94–3.11), and cough 0.97 (95% CI: 0.47–2.03) for those with a TEP over 100. Conclusions. Shopkeepers working in heavily trafficked roadside shops suffer from respiratory morbidity and the risk increases with higher TEP. Total exposure period is a valuable indicator to estimate the effects of long-term TRAP exposure. Informed Consent. Obtained Ethics Approval. The study was approved by the Institutional Ethics Committee of the National Institute for Research in Environmental Health (Bhopal, India). Competing Interests. The authors declare no competing financial interests.