Mediation effect of serum zinc on insulin secretion inhibited by methyl tert-butyl ether in gas station workers.

Methyl tert-butyl ether (MTBE), a type of gasoline additive, has been found to affect insulin function and glucose homeostasis in animal experiments, but there is still no epidemiological evidence. Zinc (Zn) is a key regulatory element of insulin secretion and function, and Zn homeostasis can be disrupted by MTBE exposure through inducing oxidative stress. Therefore, we suspected that Zn might be involved and play an important role in the process of insulin secretion inhibited by MTBE exposure. In this study, we recruited 201 male subjects including occupational and non-occupational MTBE exposure from Anhui Province, China in 2019. Serum insulin and functional analog fibroblast growth factor 1 (FGF1) and blood MTBE were detected by Elisa and headspace solid-phase microextraction and gas chromatography-high-resolution mass spectrometry. According to MTBE internal exposure level, the workers were divided into low- and high-exposed groups and found that the serum insulin level in the high-exposed group was significantly lower than that in the low-exposed group (p = 0.003) while fasting plasma glucose (FPG) level increased obviously in the high-exposed group compared to the low-exposed group (p = 0.001). Further analysis showed that MTBE exposure level was positively correlated with FPG level, but negatively correlated with serum insulin level, which suggested that the FPG level increase might be related to the decrease of serum insulin level induced by MTBE exposure. The results of further mediation effect analysis showed that changes in serum zinc levels played a major intermediary role in the process of insulin secretion inhibition and blood glucose elevation caused by MTBE exposure. In addition, a significant negative correlation was found between MTBE exposure and serum Zn level, which might play a strong mediating effect on the inhibition of insulin secretion induced by MTBE exposure. In conclusion, our study provided evidence that MTBE could inhibit insulin secretion and interfere with Zn metabolism in gas station workers for the first time, and found that Zn might play an important mediation effect during the process of inhibiting insulin secretion and interfering with glucose metabolism induced by MTBE exposure.

Complex Refractory Esophageal Stricture Due to Chronic Gasoline Ingestion: A Case Report.

Esophageal stricture is a narrowing of the esophageal lumen which is often characterized by impaired swallowing or dysphagia. It can be induced by inflammation, fibrosis or neoplasia which damages the mucosa and/or submucosa of the esophagus. Corrosive substance ingestion is one of the major causes of esophageal stricture, particularly in children and young adults. For instance, accidental ingestion or attempted suicide with corrosive household products is not uncommon. Gasoline is a liquid mixture of aliphatic hydrocarbons derived from the fractional distillation of petroleum, which is then combined with additives such as isooctane and aromatic hydrocarbons (e.g., toluene and benzene). Gasoline also contains several other additives including ethanol, methanol and formaldehyde, which make it a corrosive agent. Interestingly, to the best of our knowledge, the incidence of esophageal stricture caused by chronic gasoline ingestion has not been reported. In this paper, we report the case of a patient with dysphagia due to complex esophageal stricture due to chronic gasoline ingestion who underwent a series of esophago-gastro-duodenoscopy (EGD) procedures and repeated esophageal dilation.

Residential proximity to petrol stations and risk of childhood leukemia.

Petrol stations emit benzene and other contaminants that have been associated with an increased risk of childhood leukemia. We carried out a population-based case-control study in two provinces in Northern Italy. We enrolled 182 cases of childhood leukemia diagnosed during 1998-2019 and 726 age- and sex-matched population controls. We geocoded the addresses of child residences and 790 petrol stations located in the study area. We estimated leukemia risk according to distance from petrol stations within a 1000 m buffer and amount of supplied fuel within a buffer of 250 m from the child's residence. We used conditional logistic regression models to approximate risk ratios (RRs) and 95% confidence intervals (CIs) for associations of interest, adjusted for potential confounders. We also modeled non-linear associations using restricted cubic splines. In secondary analyses, we restricted to acute lymphoblastic leukemia (ALL) cases and stratifed by age (<5 and ≥5 years). Compared with children who lived≥1000 m from a petrol station, the RR was 2.2 (95% CI 0.5-9.4) for children living<50 m from nearest petrol station. Associations were stronger for the ALL subtype (RR=2.9, 95% CI 0.6-13.4) and among older children (age≥5 years: RR=4.4, 95% CI 0.6-34.1; age<5 years: RR=1.6, 95% CI 0.1-19.4). Risk of leukemia was also greater (RR=1.6, 95% CI 0.7-3.3) among the most exposed participants when assigning exposure categories based on petrol stations located within 250 m of the child's residence and total amount of gasoline delivered by the stations. Overall, residence within close proximity to a petrol station, especially one with more intense refueling activity, was associated with an increased risk of childhood leukemia, though associations were imprecise.

Micronucleus assay in the exfoliated cells of buccal mucosa of gasoline station workers in Tehran.

Objectives: One of the most critical landmarks of DNA damage is the micronucleus assay. Enumeration of micronuclei contributes to the early diagnosis of precancerous lesions and cancers; however, there are few studies on the frequency of micronucleus in gasoline station workers. To the best of our knowledge, no study has addressed this issue in Iran. The present study aimed to determine the role of working in the gasoline stations of Tehran city on micronucleus frequency in buccal mucosa. Materials and Methods: In this historical cohort study, buccal mucosa samples were collected from 110 individuals working at gasoline stations and 100 unemployed persons using wet tongue depressors. After Papanicolaou staining, the percentage of cells containing micronucleus as well as the mean number of micronucleus in the micronucleated cells was reported. Student's t-test, Mann-Whitney test, and regression analyses were used to specify the effect of other variables on the frequency and mean number of micronucleus per cell. Results: The mean frequency of micronucleus in the case and control group was 29.8 ± 8.2 and 9.3 ± 3.2, respectively, which was statistically significant (P = 0.0001). Furthermore, the mean number of micronucleus in the micronucleated cells of buccal mucosa was significantly higher in individuals who were exposed to gasoline than the control group (P = 0.0001). Conclusion: The results indicated that exposure to gasoline could increase the frequency of micronucleus. It was also revealed that cigarette and hookah smoking and alcohol consumption, together with working in gasoline stations, increase micronucleus abundance, implying the cumulative carcinogenic effect of these factors.

Inflammatory and proapoptotic effects of inhaling gasoline fumes on the lung and ameliorative effects of fenugreek seeds.

Impacts of inhaling gasoline fumes on the lungs of adult male rats and the alleviating role of fenugreek seeds were evaluated. Twenty-four rats were divided into four groups, unexposed control and fenugreek groups, gasoline exposed groups for 6 h/6 day/week for 10 weeks with and without supplementation of fenugreek seed powder in food (5% w/w). Rats exposed to gasoline fumes showed significant elevation in lung tumor necrosis factor-α, as an inflammatory marker, and the proapoptotic marker Bax with a reduction in the antiapoptotic marker Bcl2. Moreover, remarkable elevations in transforming growth factor-ß1, collagen and hydroxyproline were observed as fibrotic markers. Lung oxidative stress markers (hydrogen peroxides, malondialdehyde, and protein carbonyl) increased significantly along with marked decrease in total antioxidant capacity, superoxide dismutase, and catalase levels. Additionally, marked decreases in white and red blood cell counts, hemoglobin content, platelet count, accompanied by elevated red cell distribution width percentage were observed, supporting the inflammatory status. Histopathological changes represented by hematoxylin&eosin, immunohistochemistry staining for Bax&Bcl2, and transmission electron microscopy supported the negative impacts of gasoline fumes compared to the control group. Fenugreek seeds supplementation with gasoline exposure showed pronounced alleviation of lung biochemical and histopathological changes compared to the gasoline-exposed group.

The end of the assembly line: Shifting patterns of automotive burns.

INTRODUCTION: As recently as 2006, carburetor flash burns comprised as much as 27% of admissions for car-related burns, despite the fact carburetors were last installed in pre-1990 automobiles. The prevalence of this injury pattern is related to the estimated 14 million cars on the road today that were manufactured prior to that year. The aim of this study was to investigate modern sources of automotive burns and describe any new trends in automotive burn-related epidemiology. MATERIALS AND METHODS: A retrospective review was conducted of all burn admissions from the years 2009-2013 to identify patients who suffered automotive-related burns. Pediatric patients (<18 years old) were excluded. Demographic information including age, gender, mechanism of injury, occupation, TBSA, number of operations, and length of hospital stay were recorded. RESULTS: From 2009-2013, the burn center saw 83 admissions for automotive-related burns. 14.5% of patients were mechanics. The most common injury pattern was from radiator burns (47%), followed by gasoline related burns (30%). There were only two carburetor burns (2.4%). 67.4% of patients were treated for less than two hospital days and there was one death (1.2% mortality). CONCLUSION: Despite the removal of carburetors from engines and a decrease in this specific mechanism, a significant morbidity remains with gasoline-inflicted burns. More public awareness is needed for the safe removal of radiator caps and handling of chemicals in overheating engines.

Assessment of liver and renal function tests among gasoline exposed gas station workers in Mekelle city, Tigray region, Northern Ethiopia.

BACKGROUND: Volatile organic compounds such as gasoline and other fuels are associated with a wide variety of deleterious health effects including liver and kidney diseases. Gasoline station workers are exposed to a mixture of hydrocarbons during dispensing. However, no published studies investigated the liver and renal function tests of gasoline station workers in Ethiopia. Therefore the aim of this study was to assess liver and renal function tests among gasoline station workers. METHOD: A comparative cross sectional study was conduct from January 2018 to April 2018 at Mekelle city, Tigray region, Northern Ethiopia. Liver and renal function tests were analyzed on gasoline exposed (n = 43) and controls (n = 47) by Pentra C400 automated clinical chemistry analyzer. Student independent t-test and one way-ANOVA statistical methods were employed using SPSS Ver23. P-value < 0.05 was regarded as statistically significant. RESULT: The mean level of ALT, AST, Urea, creatinine, and uric acid was significantly higher among gasoline stations workers when compared to control study participants. There was also a significant increase in ALT, AST, Urea, creatinine and uric acid among gasoline stations with above 6 years exposure when compared with those exposed for ≤2 and3-6years. CONCLUSION: These findings suggest that increasing liver and renal parameters may be associated with exposure to gasoline and it is dependent on time of exposure to gasoline.

Down-regulation of diesel particulate matter-induced airway inflammation by the PDZ motif peptide of ZO-1.

Although diesel airborne particulate matter (PM2.5) has been known to play a role in many human diseases, there is no direct evidence that therapeutic drugs or proteins can diminish PM2.5-induced diseases. Nevertheless, studies examining the negative control mechanisms of PM2.5-induced diseases are critical to develop novel therapeutic medications. In this study, the consensus PDZ peptide of ZO-1 inhibited PM2.5-induced inflammatory cell infiltration, pro-inflammatory cytokine gene expression, and TEER in bronchoalveolar lavage (BAL) fluid and AM cells. Our data indicated that the PDZ domain in ZO-1 is critical for regulation of the PM2.5-induced inflammatory microenvironment. Therefore, the PDZ peptide may be a potential therapeutic candidate during PM-induced respiratory diseases.

Effect of occupational exposure to petrol and gasoline components on liver and renal biochemical parameters among gas station attendants, a review and meta-analysis.

OBJECTIVES: Kidney and liver are of the most affected organs during permanent exposure to petrol and gasoline components in gas stations. This study aims to investigate the renal and liver involvements in these workers using meta-analysis. METHODS: PubMed, Scopus, Science direct, ISI web of science, and Google scholar motor engine were searched using Mesh terms of the relevant keywords. Screening of titles, abstracts and full texts was continued until the eligible articles meeting the inclusion/exclusion criteria were selected. Quality assessment was conducted using NOS (Newcastle-Ottawa Quality score). The pooled standard mean difference of the renal and liver indices between exposed/unexposed groups was estimated using Stata ver. 11 software. RESULTS: In this systematic review, 22 papers were entered. The pooled standard mean difference (95% confidence interval) between exposed and unexposed groups was estimated as of 0.74 (0.28, 1.21) for alkaline phosphatase (ALP), 2.44 (1.80, 3.08) for aspartate transaminase (AST), 2.06 (1.42, 2.69) for alanine transaminase (ALT), 0.10 (-0.09, 0.29) for total Bilirubin (TB), 0.74 (-0.42, -1.90) for total protein (TP), -0.49 (-0.82, -0.15) for albumin, 0.88 (-0.10, 1.87) for uric acid, 1.02 (0.45, 1.59) for creatinine and 1.44 (0.75, 2.13) for blood urea nitrogen (BUN). CONCLUSION: Our meta-analysis showed that the serum AST, ALT, ALP, total protein, total bilirubin, BUN, uric acid and creatinine levels were higher among workers exposed to petrol and gasoline than control group, while albumin was lower in the serum of the exposed workers. Therefore, occupational exposure to gasoline stations can create adverse effects on kidney and liver function.

Headache and Osmophobia in Gas Station Workers Exposed to Gasoline Odor.

INTRODUCTION: Headache attacks may be triggered by several factors, among them odors, especially in migraine patients. OBJECTIVES: The aim of this study wasto determine the association between gasoline odor and headache attacks in patients with migraine or tension-type headache (TTH). SUBJECTS AND METHODS: The study was prospective, cross-sectional, with comparison of groups, using nonrandom sample and convenience. Fifty-two gas station workers diagnosed with migraine or TTH according to ICHD-3 criteria were interviewed on the relationship between gasoline odor and headache. RESULTS: Of the 52 gas station workers with headaches, there were 39 (75%) with migraine without aura and 13 (25%) with TTH. The age ranged from 19 to 50 years, with a mean of 29.5 ± 7.2 years. Osmophobia during headache attacks predominated in workers with migraine (29/39; 74.4%). The onset of headache due to odor exposure occurred in 23/39 (60%) of the workers with migraine and in 2/13 (15.4%) in TTH. These differences were statistically significant (χ2 = 7.4; p = 0.016). Osmophobia in the absence of pain (period between attacks) predominated in workers with migraine (17/39, 43.6%), but with no statistical value. CONCLUSIONS: Gas station workers diagnosed with migraine or TTH may experience osmophobia and headache triggered by the odor of gasoline.

Hypermethylation in Gene Promoters Are Induced by Chronic Exposure to Benzene, Toluene, Ethylbenzene and Xylenes.

BACKGROUND AND OBJECTIVE: Gas station attendants are occupationally exposed to benzene, toluene, ethylbenzene and xylene (BTEX) compounds and thus more susceptible to the biological effects of this mixture present in gasoline, especially due to the carcinogenicity of benzene. Furthermore, the harmful effects of BTEX exposure may be potentiated by genetic and epigenetic inactivation of critical genes. The objective was to evaluate such gene-BTEX interactions accessing the promoter methylation status of p14ARF, p16INK4A and GSTP1 in peripheral blood leukocyte samples. MATERIALS AND METHODS: The 59 exposed and 68 unexposed participants from Rio de Janeiro, Brazil, were included. The promoter methylation status was accessed by methylation-specific PCR (MSP) and GSTP1 Ile105Val polymorphism was investigated by PCR-restriction fragment length polymorphism (PCR-RFLP) technique. RESULTS: Both p14ARF and p16INK4A were significantly hypermethylated in exposed subjects compared to unexposed (p = 0.004 and p<0.001, respectively). Additionally, p16INK4A hypermethylation in the exposed group was correlated with chromosomal abnormalities (CAs) (p = 0.018), thus highlighting the influence of the gene-environment interactions on genome instability. Noteworthy, p16INK4A methylation was significantly associated with miscarriage among female attendants (p = 0.047), in which those who reported miscarriage exhibited hypermethylation in at least 2 of the 3 genes analyzed. The GSTP1 heterozygote genotype, which could affect the metabolism of benzene detoxification, was found in both groups but was more frequent in those occupationally exposed. No significant association was observed between GSTP1 genotypes and methylation status. CONCLUSION: Together, these findings indicate that gas station attendants with the aforementioned epigenetic and genetic profiles may be at greater risk of occupational BTEX exposure-induced genome instability, which could require concerted efforts to establish more preventive actions and constant biomonitoring in gas station attendants.

Inhibitory effect of particulate matter on toll-like receptor 9 stimulated dendritic cells by downregulating mitogen-activated protein kinase and NF-κB pathway.

Ambient particulate matter (PM) is associated with adverse health consequences. However, the influence of PM on the innate immune system is poorly understood. The aim of the present study was to examine the effect of diesel particulate matter 2.5 µm (PM2.5, SRM1650b) on dendritic cells. PM2.5 significantly reduced cytokine levels of interleukin (IL)-12 p40, IL-6 and TNF-α levels in CpG-DNA (TLR9 ligand)-stimulated dendritic cells. To determine the mechanisms underlying this observed inhibition induced by PM2.5, western blot analysis was conducted. PM2.5 was found to downregulate ERK1/2, JNK1/2, p38 MAPKs, and NF-κB pathways. PM2.5 exposure decreased TLR9-dependent NF-κB and activator protein (AP-1) reporter luciferase activities. Our findings demonstrate that PM2.5 reduced the production of cytokines which may be associated with inhibition of MAPK and NF-κB signaling pathway. Further, data suggest the immunosuppressive effect of PM2.5 on the innate immune cells may lead to serious damage to the host immune system.

Omega 3 Supplementation Can Regulate Inflammatory States in Gas Station Workers: A Double-Blind Placebo-Controlled Clinical Trial.

Environmental exposure to diesel particulate matter and commercial gasoline in gas station workers might induce oxidative stress and changes in the balance of the immune system. In this study, the immunomodulatory impacts of omega 3 fatty acid (ω3FA) supplement were assessed on inflammatory and anti-inflammatory markers in gas station workers in a double-blind placebo-controlled clinical trial. Fifty-three men working in gas stations were treated with ω3FA (n = 29) or placebo (n = 24) for 60 days. C-reactive protein, interleukin-12 (IL-12), transforming growth factor ß (TGF-ß), interferon γ (IFN-γ), tumor necrosis factor α, IL-10, and IL-17 levels were measured by enzyme-linked immunosorbent assay method before and after the completion of the trial. The concentrations of IFN-γ and IL-17 were significantly decreased in ω3FA group compared with the placebo group (P < 0.001). Moreover, the levels of inhibitory cytokines including TGF-ß and IL-10 significantly were increased in ω3FA group (P < 0.001). Overall, ω3FA nutritional supplementation can be useful in reducing inflammatory immune responses and maintaining immune tolerance in people with high exposure to inflammation-inducing factors. [Figure: see text].

Sustainable remediation of diesel-contaminated soil by low temperature thermal treatment: Improved energy efficiency and soil reusability.

Thermal treatment can effectively remediate diesel-contaminated soil, but is considered unsustainable because of its energy-intensive nature and potential to damage soil properties. Here, we used low temperature thermal treatment (LTTT) as an energy-efficient technique to remediate diesel-contaminated soil. The impacts of LTTT on the physiochemical and ecological properties of soils were investigated to evaluate the reusability of heated soil. Heating at 250 °C for 10 min reduced the concentration of the total petroleum hydrocarbons from 6271 mg/kg to 359  mg/kg, which is lower than the Chinese risk screening level of 826 mg/kg. After LTTT, most soil physiochemical properties were nearly unchanged, and the NO3--N and NH4+-N contents increased. Moreover, LTTT-remediated soil was favorable for the germination and early growth of wheat. The microbial community changed substantially, but recovered after being mixed with uncontaminated soil. Finally, exploration of the mechanisms of LTTT revealed that pyrolysis was the dominant mechanism of diesel removal. A biochar-like pyrolytic carbon was formed, which improved the soil reusability.

The effect of occupational exposure to petrol on pulmonary function parameters: a review and meta-analysis.

Introduction Exposure to petrol and gasoline can have harmful effects on the lungs. This review aimed to summarize the reported effects of this exposure on pulmonary function parameters. Methods Relevant studies were identified by a comprehensive search in PubMed, Scopus, Science Direct and Google Scholar databases. Irrelevant studies were excluded. Quality assessment was performed using the Newcastle-Ottawa score (NOS). The standard mean difference of pulmonary parameters between exposed and unexposed petrol station attendants was pooled using random effects. Meta-regression was used to investigate factors probably related to heterogeneity. Studies affecting the total estimates were assessed during sensitivity analysis. The Egger test was performed to investigate any evidence of publication bias. Results Eventually, 26 studies entered the meta-analysis, and the pooled standard difference [95% confidence interval (CI)] of forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC, vital capacity (VC), peak expiratory flow (PEF), forced expiratory flow (FEF25-75) and maximum voluntary ventilation (MVV) in the exposed minus unexposed groups was -1.08 L (95% CI: -1.38, -0.78), -0.92 L (-1.15, -0.69), -0.65 (-1.01, -0.30), -0.51 L (-0.96, -0.06), -0.96 L/s (-1.21, -0.69), -0.78 L/s (1.14, -0.42) and -0.58 L/min (-0.90, -0.27), respectively, and showed a decrease in all pulmonary parameters in the exposed group. Conclusion Occupational exposure to petrol fumes is a risk factor for lung function and there is a reverse relation between lung function and the duration of exposure.

Imunophenotypic Evaluation as a Tool for Monitoring Risks for Blood Malignancies in Gas Station Workers.

Background: Gas station workers are exposed to carcinogenic substances with impact on the hematologic and immune systems. The aim was to apply the immunophenotyping as a tool in the biological monitoring. Methods: This is a workplace-based case-control study with 49 workers and 26 controls. Medical interviews, hematological exams, and immunophenotyping analyses were performed. According to risk behavior (cleaning flannel and mistrust in the automatic fuel supply) the workers were divided into two groups: low risk (group 1) and high risk (group 2). Results: The results showed that CD16, HLA-DR, CD25, CD56+, CD16 CD56 low, and CD56 high expressions were higher in workers when compared to the control group (P =0.020, P =0.001, P =0.001; P =0.034, P=0.023, and P =0.008, respectively). The expressions of CD2, CD8, CD10, CD8low, and CD4/CD8 ratios were lower (P =0.016, P =0.001, P=0.001, P= 0.017, P = 0.0259, and P =0.029, respectively). Headache and paresthesia complaints were associated with workers when compared to the control group (OR = 4.091, 95% CI, 1.400 -11.951, P = 0.014; OR =12.12, 95% CI, 1.505 - 97.61, P =0.004). Using cleaning flannel and mistrust in the automatic fuel supply (risk behaviors) were associated with group 2 (OR = 9.71, 95% CI, 2.60-36.26, P = 0.005; OR = 18.18, 95% CI, 2.04-161.37, P = 0.004). Conclusions: The results strengthen the worker's immunosuppression hypothesis, which may contribute to some disorders and the carcinogenesis process. The evaluation of the immune system by flow cytometry is a promising tool for monitoring blood malignancy risk in addition to regular classic hematological exams.

Auditory system dysfunction in Brazilian gasoline station workers.

Objective: To examine the auditory system of Brazilian gasoline station workers using an extensive audiological test battery. Design: This was a cross-sectional study. The audiological evaluation included a questionnaire, pure-tone audiometry, acoustic immittance tests, transient-evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAEs), auditory brainstem response (ABR) and P300 auditory-evoked potentials. Study sample: A total of 77 Brazilian gasoline station workers were evaluated, and their results were compared with those of 36 participants who were not exposed to chemicals or noise at work. The gasoline station employees worked in 18 different gas stations, and the noise area measurements from all gas stations revealed time-weighted averages below 85 dBA. Results: Of the 77 gasoline station workers evaluated, 67.5% had audiometric results within the normal range, but 59.7% reported difficulties in communication in noisy places. Gasoline station workers showed significantly poorer results than non-exposed control participants in one or more conditions of each of the audiological tests used, except P300. Conclusions: The results suggest that the gasoline station workers have both peripheral and central auditory dysfunctions that could be partly explained by their exposure to gasoline.

Co-inoculation of Arizona cypress with arbuscular mycorrhiza fungi and Pseudomonas fluorescens under fuel pollution.

Air pollution in metropolitan areas of Iran has negatively impacted establishment, growth, and development of many woody plant species, threatening the health of urban forest species. This study was designed to investigate the effects of artificial inoculation of seedlings of a major urban forest tree, Arizona cypress (Cupressus arizonica Greene) with beneficial microorganisms under the stress of air pollution caused by exhaust emissions from fuel pollutants (FP). We conducted this research as a completely randomized design in a form of split-factorial with three factors comprising arbuscular mycorrhizal fungi (AMF) inoculation with Rhizophagus irregularis or Funneliformis mosseae or a mixture of both species, bacterial inoculation with Pseudomonas fluorescens and non-inoculated controls, and two levels of FP (fuel pollutants and non-fuel pollutants) using three replications of each treatment. Fuel pollutants significantly reduced root colonization, shoot and root dry weight, nutrient concentrations (N, P, K, and Fe), glomalin-related soil protein (GRSP), and chlorophyll concentration, while increasing proline content, enzyme activity, malondialdehyde (MDA), and hydrogen peroxide (H2O2) concentrations in Arizona cypress seedlings. Nevertheless, adverse effects of FP in the inoculated plants (especially AMF plants) were less than in the non-inoculated plants. Inoculations of AMF especially the mixture of both mycorrhizal species effectively alleviated the negative effects of FP on Arizona cypress seedlings. This promising effect was related to increased GRSP content in the media which improved concentrations of N, P, and Fe in plants, enhanced chlorophyll concentration, and elevated enzymatic antioxidants such as ascorbate peroxidase and glutathione peroxidase which resulted in increased dry mass of the plants under air pollution stress.

Response of the Native Springtail Parisotoma insularis to Diesel Fuel-Contaminated Soils Under Field-Realistic Exposure Conditions at Subantarctic Macquarie Island.

A number of sites contaminated by petroleum hydrocarbons from past fuel spills are currently undergoing remediation on subantarctic Macquarie Island (under the jurisdiction of Tasmania, Australia). To assess the environmental risks these spills pose, and to establish remediation targets and guideline values, toxicity data for a range of native biota are required. The availability of data for local biota is limited, especially for soil invertebrates, which are critical to soil health. To examine the response of naturally occurring soil invertebrate communities to fuel contamination, intact soil cores from a range of soil types were collected along an organic carbon (OC) gradient. Organic carbon was factored into the toxicity assessment due to its toxicity-modifying potential. Soil cores were spiked with Special Antarctic Blend diesel, to mimic a fresh fuel spill at the soil surface. Springtails were the most abundant taxa, with the community heavily dominated by the native species Parisotoma insularis. This species was sensitive to fuel contamination (EC20 48 mg/kg, CI 5-188), irrespective of soil organic content. This study is the first to derive critical effect concentrations (CECs) for a subantarctic springtail species and provides important data that will be incorporated into future derivation of site-specific soil quality guideline values for fuels for Macquarie Island soils and the broader subantarctic region. Integr Environ Assess Manag 2019;15:565-574. © 2019 SETAC.