Systematic Review of Exposure to Polycyclic Aromatic Hydrocarbons and Obstructive Lung Disease

Background. There is fast-growing epidemiologic evidence of the effects of environmental chemicals on respiratory health. Polycyclic aromatic hydrocarbons (PAHs) have been linked with airway obstruction common in asthma and/or asthma exacerbation, and chronic bronchitis and emphysema. Objectives. A systematic review of the association between exposure to PAHs and obstructive lung diseases is not yet available. The present systematic review aims to evaluate the evidence available in epidemiological studies that have associated PAHs with obstructive lung diseases such as asthma, chronic bronchitis, emphysema. Methods. We performed a systematic literature search on PubMed, Google Scholar, and Scopus databases using relevant keywords and guided by predesigned eligibility criteria. Results. From the total of 30 articles reviewed, 16 articles examined the link between PAHs and lung function in both adults and children. Twelve articles investigated the association between PAHs and asthma, asthma biomarkers, and/or asthma symptoms in children. Two articles studied the relationship between PAHs and fractional exhaled nitric oxide (FeNO), a biomarker of airway inflammation and the relationship between PAHs and obstructive lung diseases and infections, respectively. One study assessed exposure to daily ambient PAHs and cough occurrence. Discussion. Twenty-seven studies found an association between PAHs and asthma and reduced lung function. In children it is reinforced by studies on prenatal and postnatal exposure, whereas in adults, reductions in lung function tests marked by low forced expiratory volume in 1 second, (FEV1), forced vital capacity (FVC), and forced expiratory flow (FEF25–75%) were the major health outcomes. Some studies recorded contrasting results: insignificant and/or no association between the two variables of interest. The studies reviewed had limitations ranging from small sample size, to the use of cross-sectional rather than longitudinal study design. Conclusions. The literature reviewed in the present study largely suggest positive correlations between PAHs and obstructive lung diseases marked mainly by asthma and reduced respiratory function. This review was registered with PROSPERO (Registration no: CRD42020212894) Competing Interests. The authors declare no competing financial interests.

Critical Review of Lead Pollution in Bangladesh

Background. Lead (Pb) poses a severe threat to human health and the environment. Worldwide Pb production and consumption have significantly increased along with unplanned industrialization and urbanization, lead smelting, and lead-acid battery processing. The improper management of Pb-containing elements is responsible for Pb pollution. Lead's persistence in nature and bioaccumulation in the food chain can lead to adverse health impacts. Objectives. The present study aims to describe Pb contaminated sites in Bangladesh and Pb concentration in the atmosphere, water, sediments, soil, vegetables, fish, and other foods in Bangladesh. Methods. The present study searched a total of 128 peer-reviewed articles based on a predefined set of criteria (keywords, peer-reviewed journals, and indexing in Scopus, Science Direct, Web of Science, Springer, PubMed, Directory of Open Access Journals (DOAJ), and Bangladesh Journals Online (BanglaJOL) and exclusion criteria (predatory journal and absence of full text in English) and finally selected 63 articles (58 research articles and five (5) reports). The relevant findings on Pb exposure, sources, routes, diet, and impacts in Bangladesh were combined and presented. Results. The reviewed studies identified 175 Pb contaminated sites through soil sample assessment in Bangladesh. The study determined Pb concentrations in air (0.09–376.58 μg/m3, mean 21.31 μg/m3), river water (0.0009–18.7 mg/l, mean 1.07 mg/l), river sediments (4.9–69.75 mg/kg, mean 32.08 mg/kg), fish (0.018–30.8 mg/kg, mean 5.01 mg/kg), soil (7.3–445 mg/kg, mean 90.34 mg/kg), vegetables (0.2–22.09 mg/kg, mean 4.33 mg/kg) and diet items (0.001–413.9 mg/kg, mean 43.22 mg/kg) of which 38.8%, 27.8%, 54.5%, 68.8%, 9.7% and 100% of samples, respectively, exceeded related World Health Organization (WHO), Food and Agriculture Organization (FAO), United States Environmental Protection Agency (USEPA) and Bangladesh Standard Testing Institution (BSTI) guidelines. The present study found that industrial soils are severely polluted with Pb (7.3–445 mg/kg) in Bangladesh. A high Pb concentration has been found in fish muscle and foods, including leafy and non-leafy vegetables collected from different places in Bangladesh. Conclusions. Lead-contaminated foods can enter the human body through dietary intake and consequently lead to long-term adverse health effects. This study may help policymakers to formulate national policies with effective mitigation plans to combat the adverse health impacts of Pb in Bangladesh. Competing Interests. The authors declare no competing financial interests.

Determination of Perflourooctanoic Acid Toxicity in a Human Hepatocarcinoma Cell Line

Background. Perfluorooctanoic acid (PFOA) is used in different industrial and commercial products. Research shows the presence of PFOA in home dusts, tap and surface water, and in biological samples. The International Agency for Research on Cancer (IARC) has classified PFOA as a possible carcinogen for humans. The liver is thought to be a target organ of PFOA accumulation and toxicity. Objective. Some studies have found toxic effects on the liver and related mechanisms; however, more studies are needed to better understand PFOA - induced hepatotoxicity. Methods. In the present study, a human hepatocarcinoma cell line was exposed to PFOA for 24 hours and cell viability, apoptosis, the oxidative system and immune response were evaluated. Results. While apoptosis was the main cell death pathway at low concentration (86.5%), the necrotic cell fraction increased with higher concentrations (46.7%). Significant changes in the reactive oxygen species (5.3-folds) glutathione (GSH) (1.7-folds) and catalase (CAT) (1.4-folds) levels were observed, as well as changes to interleukin-6 (≤1.8-fold) and interleukin-8 levels (35–40%). Conclusions. In light of the data, PFOA is potentially hepatotoxic through the investigated pathways. The results represent a background for future in vivo mechanistic studies. Competing Interests. The authors declare no competing financial interests.

Pesticide Spraying and Reduced Cholinesterase Activity among Hill Tribe Farmers in Thailand

Background. Farming is an important occupation in Thai hill tribe communities, which are often remote, and lack other economic opportunities along with basic educational, health care, and occupational health and safety services. Additionally, these communities have a unique culture and language. Objectives. The present study was conducted in northern Thailand to evaluate pesticide exposures and associated health impacts among hill tribe farmers, and to compare them to Thai farmers. Methods. Lahu hill tribe farmers in a mountain community were recruited by public health hospital staff, along with a reference group of lowland Thai farmers. Participants completed a survey on demographic factors and work practices, and blood and urine samples were collected by a trained nurse. Acetylcholinesterase activity (AChE) was quantified to assess pesticide exposure, whereas liver and kidney functions were evaluated using clinical biomarkers. Results. A large fraction (nearly 50%) of Lahu farmers were illiterate and could not speak Thai. Thai farmers worked fewer hours per week (39.4) than did Lahu farmers. Among Lahu farmers, AChE levels were significantly lower (worse) than those of Thai farmers. However, other health outcomes in these populations were similar. Formal education and language skills were not associated with pesticide exposures or health outcomes. Pesticide spraying was found to be a significant predictor of reduced AChE (OR=8.5, 95% CI 1.1–69.6). Conclusions. Pesticide exposures are a significant occupational health hazard among Thai hill tribe farmers. Training, potentially delivered by community health volunteers, is needed to communicate safe pesticide work practices to these farmers. Participant Consent. Obtained Ethics Approval. The study protocol was approved by the Institutional Review Board of Mae Fah Luang University (REH-61080). Competing Interests. The authors declare no competing financial interests.

Assessment of Heavy Metals and Related Impacts on Antioxidants and Physiological Parameters in Oil Refinery Workers in Iraq

Background. Some heavy metals can be harmful to human health in elevated doses such as zinc (Zn) and magnesium (Mg), while others such as lead (Pb), cadmium (Cd), mercury (Hg), and copper (Cu) have harmful consequences to health even in small doses. Heavy metals and additives are incorporated into crude oil to enhance performance.3,4,5 Crude oil is well known to contain heavy metals like Cu, Cd, Ni and Pb.3,6,7 Objective. The current study aimed to assess levels of heavy metals and the impact of these metals on antioxidant levels and physiological variables in the serum of oil refinery workers in Iraq. Methods. Heavy metals such as Pb, Cd, Hg, Zn, Cu and Mg were assessed in the serum of a sample of refinery workers (N=40) and a control group (N=20) using atomic absorption spectrometry (AAS). Additionally, levels of malondialdehyde (MDA), δ-aminolaevulinic acid dehydratase (ALAD) and total antioxidant capacity (TAC), and physiological variables such as blood urea, serum creatinine, glutamate-oxaloacetic transaminase (GOT), glutamate-pyruvic transaminase (GPT), and gamma-glutamyl transferase (GGT) were measured to assess impact of these heavy metals. Results. Mercury, Cd, and Pb were significantly elevated in the refinery worker group in comparison with the control group, while the levels of Zn, Cu, and Mg were significantly lower in the refinery worker group compared to the control group. There was a significant difference between the control group and the worker group for most of the antioxidants and functional variables. Total antioxidant capacity (TAC), δ-aminolevulinic acid dehydratase (ALAD), and malondialdehyde (MDA) were significantly lower in the worker group while blood urea, serum creatinine, glutamate pyruvate transaminase (GPT), and gamma-glutamyl transferase (GGT) showed a significant elevation in the workers' group. Glutamic oxaloacetic transaminase (GOT) showed no significant difference between the control group and the worker group. Conclusions. Refinery workers are at increased risk of having higher serum levels of Pb, Cd, and Hg compared to controls which can lead to an increase in oxidative stress, decrease in TAC, and decrease in the essential trace elements Zn, Cu and Mg. Participant Consent. Obtained Ethics Approval. This study was approved by the ethics committee within the Nineveh Health Department, Mosul, Iraq. Competing Interests. The authors declare no competing financial interests.

Human Health Assessment of Sixteen Priority Polycyclic Aromatic Hydrocarbons in Contaminated Soils of Northwestern Algeria

Background. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental organic contaminants generated by incomplete combustion of organic materials that are widely distributed in soils. Objectives. This study represents the first attempt to examine the health toxicity of 16 detected PAHs in contaminated soil, via different exposure pathways to populations in northwestern Algeria. Methods. The toxicity equivalency quotients (TEQ) of PAHs were evaluated. The carcinogenic risk assessment of incremental lifetime cancer risk (ILCR) from ingestion, inhalation, and dermal exposure pathways to each PAH in soil are described. Results. Incremental lifetime cancer risk values were in the upper limit of the tolerable range (10−6–10−4) for adults and children. The total cancer risk of PAH-contaminated soils for children, adolescents and adults was 2.48×10−5, 2.04×10−5 and 3.12×10−5mg.kg−1d−1, respectively. The highest potential cancer risks were identified for adults and children, with adolescents having the lowest risks. Across exposure pathways, the dermal contact and ingestion pathways had the greatest contributions to the carcinogenic risk of human exposure to PAHs. Conclusions. Further research and guidelines are needed for risk assessments of PAHs in agricultural, residential/urban, and industrial areas, and further risk assessments should include risks posed by exposure through air. Competing Interests. The authors declare no competing financial interests.

Heavy Metals and Health Risks Associated with Consumption of Herbal Plants Sold in a Major Urban Market in Southwest, Nigeria

Background. Although herbal medicines play an important role as a source of medicine, concerns have been raised about the risks posed by consumption of these plants, especially if consumed above permissible levels. Objectives. This study was undertaken to assess the level of exposure, toxicity and health risk associated with the consumption of herbal plants in Ado Ekiti urban market, Nigeria. Methods. Ten commonly consumed herbal plants sold in Ado Ekiti urban market were subjected to heavy metal analysis. Health risk assessment was carried out to determine the estimated daily intake (EDI) of heavy metals, health risk index (HRI), target hazard quotient for non-carcinogenic risk and estimation of cancer risk (ECR). Results. The EDIs for lead (Pb), nickel (Ni), chromium (Cr), copper (Cu) and magnesium (Mn) were above the upper tolerable daily intake reference for all studied plant species in both children and adults, an indication that herbal use poses a short-term to long-term health risk to consumers of these herbal products. The EDI for children was significantly lower compared to that of adults, indicating higher risks for adult consumers of these herbal products. The HRI in children for Pb (Alstonia congensis, Terminalia avicennioides, Aframomum melegueta, Cymbopogon citratus and Napoleona vogelii) were greater than 1; HRI in Cu and Mn also showed an unusually high concentration, an indication that long term exposure to the consumption of these herbal plants poses a serious health risk. The HRI in children and adults follows the order Mn > Cu > Ni > Pb > Cr; cadmium (Cd) was not detected in any of the herbal plants. The ECR for Pb, Ni and Cr present in the herbal plants for children ranged between 10−6 (low) to 10−3 (high), while the ECR for Pb, Ni and Cr for herbal plants for adults ranged between 10−5 (acceptable) to 10−2 (unacceptable). For both children and adults, there is a call for concern due to ECRs above the acceptable range; the consumption of these herbal plants poses a long-term cancer risk. Conclusions. In both children and adults, ECRs for some of the herbal plants in the present study above the acceptable range present a risk to human health. The consumption of such herbal plants poses a long-term cancer risk. Competing Interests. The authors declare no competing financial interests.

Relationship between Respiratory Morbidity and Environmental Exposure to Organochlorine Pesticides in Armenia

Background. Many studies have investigated the effects of organochlorine pesticides (OCPs) on adverse health outcomes. However, studies addressing the link between respiratory health and OCPs are limited. Organochlorine pesticides are stable compounds and belong to the class of endocrine disrupting chemicals that represent a threat to global health. Objectives. The aim of the present study was to examine the association between respiratory morbidity and environmental exposure to OCPs in selected regions in Armenia. Methods. The study was carried out in Lori and Gegharkunik provinces/marzes. The prevalence rate (per 100 000 population) and the average chronological indicators (ACh) for all respiratory diseases and asthma were calculated. Concentrations of OCPs (γ-hexachlorocyclohexane (γ-HCH), dichloro-diphenyl-trichloroethane [DDT], dichlorodiphenyldichloroethylene (DDE) and dichloro-diphenyl-dichloroethane (DDD)) were determined in soil and plant product samples and the average annual total concentration (AATC) of OCPs (γ-HCH + 4,4′-DDT + 4,4′-DDE+4,4′-DDD) was calculated. Results. The ACI for all respiratory diseases showed a growth tendency in areas of Gegharkunik province ranging from 14.2 to 20.9% and an increase in asthma ranging from 9.4% to 174.6%. The highest levels of AATC of OCPs were found in soil sampled in Gegharkunik province: 9.48 ± 1.11 μg/kg and 8.10 ± 1.05 μg/kg and these levels differed significantly from those in Lori (p=0.01–0.0007). The AATC of OCPs in plant products from Gegharkunik was also statistically higher: 1.83±0.13 μg/kg, in comparison with that of Lori province 1.31±0.09 μg/kg (p = 0.001 – 0.0000). Conclusions. The results indicate that the increased tendency of respiratory diseases and asthma could be related to OCP residues found in soil and plant products in Gegharkunik province. However, the role of OCPs should not be ignored. Further research is needed to study OCP contamination dynamics and clarify the role of OCPs in respiratory morbidity. Competing Interests. The authors declare no competing financial interests.

Health Risk Assessment of Heavy Metal Accumulation in Broiler Chickens and Heavy Metal Removal in Drinking Water using Moringa Oleifera Seeds in Lomé, Togo

Background. Heavy metals are persistent in the environment and can cause bioaccumulation in the food chain. Drinking water contamination by heavy metals can pose a risk to poultry and to human health. The need for affordable, reliable and effective methods of water treatment has led to the use of plants materials, including coagulants such as Moringa oleifera seeds, to ensure poultry products are safe for consumers. Objectives. The aim of the present study was to investigate the effects of drinking water treatment by Moringa oleifera seed on the concentration and distribution of metals such as arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) in different parts of broilers chickens and theirs effects on consumer health. Methods. A total number of 264 one-day old chickens (Cobb-500) were assigned to three treatments, with 22 birds in each treatment and replicated four times: untreated well water (UW), well water treated with Moringa oleifera seeds and filtered (MOF) and well water treated with Moringa oleifera seeds but unfiltered (MOU). Thirty birds were randomly chosen from different treatments and slaughtered at day 45 of the experiment and samples of livers, kidneys, gizzards and breasts were obtained and analyzed for toxic metals concentrations using atomic absorption spectrophotometry. Results. The results indicated that the bioaccumulation of heavy metals was lower in MOF than those in UW and MOU. The target hazard quotient (THQ) for individual metals was below acceptable limits except for As and Pb in UW and MOU. The carcinogenic risk (TR) was estimated for each metal due to consumption of different types of chicken. Conclusions. Moringa oleifera seeds are an environmentally friendly natural coagulant and able to treat water containing undesirable heavy metal concentrations and ensure that poultry meat is safe for consumers. Competing Interests. The authors declare no competing financial interests. Ethics Approval. This study was approved by the ethics Committee of the University of Lomé-Togo.