Cancer risk assessment of polycyclic aromatic hydrocarbons in the soil and sediments of Iran: a systematic review study

Polycyclic aromatic hydrocarbons (PAHs) are organic pollutants containing several hydrocarbon rings affecting human health according to the published monitoring data. Most of these compounds can be absorbed by the soil and sediments due to the abundance of production resources of these compounds in the soil around the cities and sediments of the Iranian coast. Cancer risk assessment (CRA) is one of the most effective methods for quantifying the potentially harmful effects of PAHs on human health. In this study, the published papers that monitored PAHs in Iran’s soil and sediments were reviewed. The extraction of different data and their equivalent factors were performed according to BaP equivalent, which is the main factor for calculating CRA of PAHs. The highest concentrations of PAHs were found in the sediments of Assaluyeh industrial zones (14,844 μg/kg), Khormousi region (1874.7 μg/kg), and Shadegan wetland (1749.5 μg/kg), respectively. Dermal exposure to sediments was 96% in adults, and 4% in children, and ingestion exposure to sediment was 99% in adults and 99.2% in children. Children dermal exposure to soil was 53%, and the accidental exposure to soil was 47%. In adults, dermal exposure to soil was 96% and the accidental exposure was 4%. The results of the present study indicated a significant, the carcinogenic risk of Polycyclic Aromatic Hydrocarbons in sediments of southern regions and soils of central regions of Iran is significant.

Perspective: Considerations for Prevention and Treatment of Dermal Exposure to Toxic Organophosphorus Compounds

The potential benefit of polyhydroxy fullerene nanomaterials in preventing and alleviating toxicities from cholinesterase-inhibiting organophosphorus toxicants is compared to other dermal protectants.

Dermal Exposure to the Immunomodulatory Antimicrobial Chemical Triclosan Alters the Skin Barrier Integrity and Microbiome in Mice

Triclosan is an antimicrobial chemical used in healthcare settings that can be absorbed through the skin. Exposure to triclosan has been positively associated with food and aeroallergy and asthma exacerbation in humans and, although not directly sensitizing, has been demonstrated to augment the allergic response in a mouse model of asthma. The skin barrier and microbiome are thought to play important roles in regulating inflammation and allergy and disruptions may contribute to development of allergic disease. To investigate potential connections of the skin barrier and microbiome with immune responses to triclosan, SKH1 mice were exposed dermally to triclosan (0.5–2%) or vehicle for up to 7 consecutive days. Exposure to 2% triclosan for 5–7 days on the skin was shown to increase transepidermal water loss levels. Seven days of dermal exposure to triclosan decreased filaggrin 2 and keratin 10 expression, but increased filaggrin and keratin 14 protein along with the danger signal S100a8 and interleukin-4. Dermal exposure to triclosan for 7 days also altered the alpha and beta diversity of the skin and gut microbiome. Specifically, dermal triclosan exposure increased the relative abundance of the Firmicutes family, Lachnospiraceae on the skin but decreased the abundance of Firmicutes family, Ruminococcaceae in the gut. Collectively, these results demonstrate that repeated dermal exposure to the antimicrobial chemical triclosan alters the skin barrier integrity and microbiome in mice, suggesting that these changes may contribute to the increase in allergic immune responses following dermal exposure to triclosan.

The Toxicological Risk Assessment of Dermal Exposure of Patients Exposed to Nickel and Chromium due to Application of Ointments with Marjoram Herb Extract (Majoranae Herbae Extractum) Available in Polish Pharmacies

For elemental impurities that have been studied for transcutaneous absorption, the available data are rarely suitable for proper toxicological risk assessment — there are multiple factors that can influence this dermal absorption. Hence, in our studies, we applied generic and conservative approach — cutaneous permitted daily exposure (CPDE) described in International Conference on Harmonisation’s Q3D Guideline on Elemental Impurities (ICH Q3D). The aim of this article is toxicological risk assessment (TRA) of dermal exposure of patients exposed to nickel and chromium due to application of ointments with Marjoram herb extract (Majoranae herbae extractum) available in Polish pharmacies (n = 5, because only five manufacturers produce this kind of pharmaceutical products in Poland). To make the appropriate TRA approach, we considered (1) raw results (metal per kg of ointment), (2) one-time administration of applied ointments, and (3) daily exposure versus CPDE. Due to the fact the concentrations of Ni generally present in cutaneous products as impurities are not considered sufficient to induce sensitization, the cutaneous and transcutaneous concentration limits (CTCLs) approach was applied for this element assessment. The toxicological analysis was carried out using microwave-assisted wet digestion with concentrated nitric acid and electrothermal atomization atomic absorption spectrometry. Our results show that the ointments with Marjoram herb extract from pharmacies in Poland represent a potential health hazard to patients; however, there may be a requirement for the monitoring of impurities of nickel in future. To the best of our knowledge, this paper is the first study about nickel and chromium content in ointments with Marjoram herb extract (Majoranae herbae extractum).