Plasma dopamine in workers exposed to urban stressor

Early biological effects in outdoor workers exposed to urban air pollution: A systematic review

Urban outdoor workers (OWs), identified as professionals spending most of their working shifts in an urban environment, are exposed for at least 8 h/day to traffic air pollution, leading to potential health risks. This paper reports the results of a systematic review aimed at identifying the potential health outcomes of exposure to air pollutants for OWs, focusing mainly on police officers, drivers and street vendors. Health outcomes were analysed in terms of early biological effects quantified with specific measured indicators. The main inclusion criterion was the assessment of at least one early biological effect (genetic and epigenetic damage/alterations, inflammation or oxidative stress indicators, or hormonal imbalance) in a population of OWs exposed to urban air pollution. By applying the PRISMA workflow, 82 papers were included in this study. The results showed that the measured pollutant concentrations were significantly below the current occupational limit values, while exceeds the indications of WHO for urban air pollution. This exposure led to significant alterations of biological markers in OWs with respect to non-exposed subjects. In particular, OWs presented an increased frequency of micronuclei and DNA adducts as the main DNA alterations, while police officers (a category of highly exposed OWs) showed hormonal alterations affecting mainly the hypothalamic-pituitary-gonadal axis. Concerning oxidative stress and inflammation, all the analysed matrices (i.e. blood, sputum, urine and lachrymal fluids) showed increased indices for OWs respect to non-exposed groups. Therefore, the evaluation of effect biomarkers to detect early alterations provides crucial information for supporting the occupational risk management of OWs and, at broader level, allows for an insight of the early-stage health outcomes due to urban air pollution.

Overeating and food addiction in Major Depressive Disorder: Links to peripheral dopamine

The concept of food addiction refers to addiction-like behaviours that develop in association with the intake of highly palatable foods. Previous research indicates that a high proportion of individuals with Major Depressive Disorder (MDD) meet the criteria for food addiction, and are also at an increased risk of weight gain and chronic disease. In the central nervous system, dopamine is a neurotransmitter associated with reward salience and food intake, whereas peripheral dopamine is involved in sympathetic stress regulation, digestion and gastrointestinal motility. However, little research has examined relationships between peripheral dopamine, depressive symptoms and problematic eating behaviours in MDD. Biometrics, psychopathology and plasma dopamine levels were compared between participants with MDD (n = 80) and controls (n = 60). Participants were sub-categorised into those meeting or not meeting Yale Food Addiction Scale (YFAS) criteria. Psychometric measures of mood and appetite were used to assess MDD symptoms, problematic eating behaviours and food-addiction related symptoms. Twenty-three (23; 29%) MDD participants met the Yale criteria for food addiction. Depressed individuals meeting YFAS criteria had significantly greater psychopathology scores for both mood and eating compared to depressed individuals not meeting YFAS criteria and controls. A significant interaction between food addiction status and sex was also observed for plasma dopamine levels. Plasma dopamine levels correlated positively with disordered eating behaviours in females, and negatively in males. The results provide evidence that depressogenic excess eating and weight gain are associated with peripheral dopamine levels. Longitudinal research is warranted investigating endocrine dysregulation and excess eating in MDD, which may inform interventions and reduce chronic disease risk in affected individuals.

[Oxidative Stress Derived from Airborne Fine and Ultrafine Particles and the Effects on Brain-Nervous System: Part 2]

Traffic-related air pollution is a major contributor to urban air pollution. Diesel exhaust (DE) is its most important component of near-road and urban air pollutions and is commonly used as a surrogate model of air pollution in health effects studies. In particular, diesel exhaust particles (DEPs) and nanoparticles in DEPs are the components considered hazardous for health. It is widely known that exposure to DEPs is associated with mortality caused by respiratory and cardiovascular diseases. Recently, evidence has been accumulating showing that DEPs and nanoparticles may cause neurodegenerative disorders. Here, we introduce evidence suggesting their association with these disorders. The chemical components and the translocation of DEPs and nanoparticles to the brain are described in part 1. In part 2, we introduce the mechanism of development of neurodegenerative diseases such as stroke, Alzheimer's disease, and Parkinson's disease via oxidative stress and inflammatory events. Furthermore, there are many lines of epidemiological evidence showing that the particulates impair cognitive function and ability of memory through oxidative and inflammatory events in the brain. These lines of evidences are supported by many animal experiments on neurological disorders.

Sensitive profiling of biogenic amines in human urine by capillary electrophoresis with field amplified sample injection

In order to monitor biogenic amines in human urine, a method based on field-amplified sample injection combined with capillary electrophoresis and direct UV absorption detection was developed. Dopamine, tyramine, tryptamine, serotonin and epinephrine were effectively separated and identified in human urine samples, and detection limits were 0.072, 0.010, 0.027, 0.010 and 0.120 µmol/L, respectively. Detection limits comparable to laser-induced fluorescence detection or solid phase extraction combined with capillary electrophoresis were achieved. Parameters affecting electrophoretic system detection sensitivity were investigated. Optimal separation conditions were obtained using as background electrolyte a pH 6.5 mixture of 2-(morpholino)ethanesulfonic acid 20 mmol/L and 30 mmol/L phosphate buffer, containing 0.05% hydroxypropylcellulose and 10% v/v methanol. Injections of the sample solution were performed by applying a voltage of 12 kV for 50 s. Recovery and accuracy ranged between 89.4 and 94.9%, and 89 and 112%, respectively. The method was successfully applied on actual urine samples (from a healthy volunteer): target bioamine content was consistent with endogenous levels reported in the literature. The proposed method is simple, fast and inexpensive and can be conveniently employed in work-related stress studies. The affordability and noninvasive sampling of the method allow epidemiological studies on large number of exposed persons to be performed.

Professional exposure to urban stressors and effects on urinary metanephrines

The aim of the study is to assess whether occupational exposure to urban stressors could cause alterations in urinary metanephrines levels in traffic policemen vs administrative staff of municipal police. A total of 258 subjects were included in the study: 129 traffic policemen exposed to urban stressors (68 males and 61 females) and 129 controls (68 males and 61 females). Urinary metanephrines mean levels were significantly higher in male traffic policemen compared to controls (p < 0.01). No significant differences were in female traffic policemen compared to controls. In the control group, urinary metanephrines mean levels were significantly higher in females compared to males (p < 0.01). There were no significant differences in urinary metanephrines mean levels in female traffic policemen vs male traffic policemen. The increase in urinary metanephrines mean levels observed in male exposed compared to controls could be related to chronic occupational exposure to low doses of chemical, physical and psychosocial urban stressors.