Excretion of polycyclic aromatic hydrocarbon metabolites (OH-PAHs) in cattle urine in Ghana

Exposure and Public Health Effects of Polycyclic Aromatic Hydrocarbon Compounds in Sub-Saharan Africa: A Systematic Review

BACKGROUND AND AIM

In order to achieve improved global health, environmental health risks that could affect this goal have to be reduced as much as possible. This review thus aimed at determining the exposure levels, health risk assessments, and public health effects of polycyclic aromatic hydrocarbons (PAHs) in sub-Saharan Africa (SSA). This review was developed using guidelines provided for Preferred Reporting Items for Systematic Review and Meta-Analysis. Search was done on Google Scholar, Scopus, and PubMed databases. A study was included if it was carried out in SSA from 2000 to 2020 and written in English language. Fifty-two studies were finally retained and used for the review. Extracted data included the concentrations of 8 selected priority PAHs (including the PAHs prioritized for their carcinogenic potentials), their sources and reported outcomes. In SSA, PAHs exposure has been linked to the use of unprocessed biomass fuels for cooking, release of poorly treated petrochemical effluents into water bodies, and so on. Related public health effects included the occurrence of respiratory, cardiovascular abnormalities, and so on. Others included destruction of natural biodiversity in soil, water, and atmospheric environmental media. Health risk assessments also buttressed the occurrence of these public health effects of PAHs. In SSA, the region is exposed to a substantial amount of PAHs pollution which is associated with deleterious environmental and epidemiological effects. The adoption of healthier forms of energy, a change of attitude to one that favors environmental sustainability, and proper enforcement of environmental regulations are, however, necessary for attaining environmental sanity in SSA.

Relationship between urinary metabolites of polycyclic aromatic hydrocarbons and risk of papillary thyroid carcinoma and nodular goiter: A case-control study in non-occupational populations

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to the development of certain diseases. However, the relationship between PAH exposure and thyroid disorders remains unknown. We measured 10 of the most common hydroxylated PAHs (OH-PAHs) in the urine of thyroid nodular goiter (NG) patients, papillary thyroid carcinoma (PTC) patients, and healthy controls by gas chromatography-triple-quadrupole mass spectrometry (GC-MS/MS). We found that the concentrations of 2-hydroxyfluorene (2-OH-FLU), 2-hydroxydibenzofuran (2-OH-DBF), and 1-hydroxyphenanthrene (1-OH-PHE) in the NG group, and of 2-hydroxynaphthalene (2-OH-NAP), 2-OH-DBF, and 1-OH-PHE in the PTC group were significantly higher than those in controls. In addition, participants in the high tertiles of 2-OH-FLU and 1-OH-PHE had higher risk of NG. Besides these two OH-PAHs, elevated risk of NG was observed in women in the high tertiles of 1-hydroxynaphthalene (1-OH-NAP), 2-OH-NAP, 2-OH-DBF, and 3-hydroxyfluorene (3-OH-FLU). Furthermore, participants in the high tertiles of seven OH-PAHs, namely, 1-OH-NAP, 2-OH-NAP, 2-OH-DBF, 2-OH-FLU, 3-OH-FLU, 3/9-hydroxyphenanthrene (3/9-OH-PHE), and 1-OH-PHE, had elevated risk of PTC, and females in these high tertiles had an even higher risk of PTC. Our findings suggest that PAH exposure may increase the risk of NG/PTC, and there may be a gender-specific effect of PAH exposure on the development of NG/PTC.

Phthalate Metabolites, Hydroxy-Polycyclic Aromatic Hydrocarbons, and Bisphenol Analogues in Bovine Urine Collected from China, India, and the United States

Human exposure to endocrine-disrupting chemicals (EDCs) has aroused considerable public concern over the last three decades. Nevertheless, little is known with regard to the exposure of EDCs in farm animals. In this study, concentrations of 22 phthalate metabolites (PhMs), 15 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs), and 8 bisphenols (BPs) were determined in 183 bovine urine samples collected from China, India, and the United States. The median concentrations of urinary PhMs, OH-PAHs, and BPs in bovines, collectively, were 66, 4.6, and 16 ng/mL, respectively. Mono-n-butyl phthalate (mBP; median, 14 ng/mL) and ∑₄DEHP (four secondary metabolites of di(2-ethylhexyl) phthalate; 13 ng/mL) were the dominant PhMs; hydroxy-fluorene (OH-Fluo; 1.2 ng/mL) and -phenanthrene (OH-Phen; 1 ng/mL) were the dominant OH-PAHs; and 4,4'-di-hydroxydiphenylmethane (BPF; 10 ng/mL) and 2,2-bis(4-hydroxyphenyl) propane (BPA; 6.7 ng/mL) were the dominant BPs. Bovine urine samples from India and China contained the highest concentrations of PhMs and OH-PAHs, whereas those from India and the United States contained the highest concentrations of BPs. PhM and OH-PAH concentrations were significantly higher in the urine of bulls than those of cows; no such difference was found for BPs. Our findings establish baseline exposure information about three classes of EDCs in domestic farm animals.

Occurrence and risk assessment of potentially toxic elements and typical organic pollutants in contaminated rural soils

The residual levels and risk assessment of several potentially toxic elements (PTEs), phthalate esters (PAEs) and polycyclic aromatic hydrocarbons (PAHs) in rural soils near different types of pollution sources in Tianjin, China, were studied. The soils were found to be polluted to different extents with PTEs, PAEs and PAHs from different pollution sources. The soil concentrations of chromium (Cr), nickel (Ni), di-n-butyl phthalate (DnBP), acenaphthylene (Any) and acenaphthene (Ane) were higher than their corresponding regulatory reference limits. The health risk assessment model used to calculate human exposure indicates that both non-carcinogenic and carcinogenic risks from selected pollutants were generally acceptable or close to acceptable. Different types of pollution sources and soil physicochemical properties substantially affected the soil residual concentrations of and risks from these pollutants. PTEs in soils collected from agricultural lands around industrial and residential areas and organic pollutants (PAEs and PAHs) in soils collected from agricultural areas around livestock breeding were higher than those from other types of pollution sources and merit long-term monitoring.

Sex and site differences in urinary excretion of conjugated pyrene metabolites in the West African Shorthorn cattle

Industrialization, economic and population growth rates in Ghana have increased the release of contaminants including polycyclic aromatic hydrocarbons (PAHs) into the environment through which humans and animals are exposed. Cattle is reported to be exposed to high levels of PAHs through feed and inhalation. Once exposed, PAHs are metabolized and excreted in urine, feces or bile. In a previous study, cattle in Ghana was reported to excrete high levels of 1-hydroxypyrene (1-OHPyr) due to high exposure to the parent compound, pyrene. 1-OHPyr is further metabolized to glucuronide and sulfate conjugates. Thus, the aim of this study was to investigate the sex and site differences in urinary excretion of conjugated pyrene metabolites using cattle urine collected from rural and urban sites of the Ashanti region, Ghana. From the results, geometric mean concentration adjusted by specific gravity indicated that 1-OHPyreneGlucuronide (PyG) was the most abundant conjugate followed by PyrenediolSulfate (M3). The sum of conjugated pyrene metabolites and sum of both conjugated and deconjugated pyrene metabolites correlated significantly with PyG, PydiolSulfate (M2) and PydiolSulfate (M3). The study revealed no significant difference in urinary excretion of conjugated pyrene metabolites between rural and urban sites. This indicated that similar to urban sites, cattle in rural sites were exposed to high levels of pyrene. There was no significant difference in urinary concentrations of conjugated pyrene metabolites between sexes.

Oxidative stress and respiratory symptoms due to human exposure to polycyclic aromatic hydrocarbons (PAHs) in Kumasi, Ghana

Studies of polycyclic aromatic hydrocarbons (PAHs) and its metabolites in PM10, soils, rat livers and cattle urine in Kumasi, Ghana, revealed high concentrations and cancer potency. In addition, WHO and IARC have reported an increase in cancer incidence and respiratory diseases in Ghana. Human urine were therefore collected from urban and control sites to: assess the health effects associated with PAHs exposure using malondialdehyde (MDA) and 8-hydroxy-2-deoxyguanosine (8-OHdG); identify any association between OH-PAHs, MDA, 8-OHdG with age and sex; and determine the relationship between PAHs exposure and occurrence of respiratory diseases. From the results, urinary concentrations of the sum of OH-PAHs (∑OHPAHs) were significantly higher from urban sites compared to the control site. Geometric mean concentrations adjusted by specific gravity, GM_SG, indicated 2-OHNaphthalene (2-OHNap) (6.01 ± 4.21 ng/mL) as the most abundant OH-PAH, and exposure could be through the use of naphthalene-containing-mothballs in drinking water purification, insect repellent, freshener in clothes and/or "treatment of various ailments". The study revealed that exposure to naphthalene significantly increases the occurrence of persistent cough (OR = 2.68, CI: 1.43-5.05), persistent headache (OR = 1.82, CI: 1.02-3.26), tachycardia (OR = 3.36, CI: 1.39-8.10) and dyspnea (OR = 3.07, CI: 1.27-7.43) in Kumasi residents. Highest level of urinary 2-OHNap (224 ng/mL) was detected in a female, who reported symptoms of persistent cough, headache, tachycardia, nasal congestion and inflammation, all of which are symptoms of naphthalene exposure according to USEPA. The ∑OHPAHs, 2-OHNap, 2-3-OHFluorenes, and -OHPhenanthrenes showed a significantly positive correlation with MDA and 4-OHPhenanthrene with 8-OHdG, indicating possible lipid peroxidation/cell damage or degenerative disease in some participants. MDA and 8-OHdG were highest in age group 21-60. The present study showed a significant sex difference with higher levels of urinary OH-PAHs in females than males.