Effect of chromium on the level of IL-12 and IFN-gamma in occupationally exposed workers

Occupational and Non-Occupational Exposure to Chromium Induces Oxidative Stress and DNA Damage in the Population Near Kanpur Tanneries

Background

The chrome tanning method is widely used in the Indian tannery industry. Workers from these tanneries are directly exposed to Cr compounds due to inadequate safety measures and knowledge.

Objective

This study aimed to examine oxidative stress and DNA damage in tannery workers in Kanpur exposed to Cr both in the workplace and outside of it in terms of health.

Methods

Blood samples were collected from the people of Jajmau, Kanpur, India. The study population was divided into three distinct categories. Group I comprised 100 individuals occupationally exposed to chromium (Cr) in tannery industries. Group II included 100 individuals who resided near tannery industries but were not occupationally exposed to Cr. Finally, Group III contained 100 healthy individuals who had never been exposed to Cr. Inductively coupled plasma‒mass spectrometry (ICP-MS) was used to measure Cr in all blood samples. Malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) concentrations were used to quantify oxidative stress. A comet assay was used to determine the extent of DNA damage, and the lengths of comet tails in both the exposed and control groups were measured.

Results

Cr, MDA, SOD, and DNA damage levels were significantly greater in the exposed groups than in the control groups (P < 0.001), whereas GSH levels were significantly lower (P < 0.001).

Conclusion

This study's findings indicate that timely identification of the detrimental impacts of Cr on individuals employed in tanneries is highly important for mitigating health risks and minimizing exposure.

Pollutants in aquatic system: a frontier perspective of emerging threat and strategies to solve the crisis for safe drinking water

Water is an indispensable natural resource and is the most vital substance for the existence of life on earth. However, due to anthropogenic activities, it is being polluted at an alarming rate which has led to serious concern about water shortage across the world. Moreover, toxic contaminants released into water bodies from various industrial and domestic activities negatively affect aquatic and terrestrial organisms and cause serious diseases such as cancer, renal problems, gastroenteritis, diarrhea, and nausea in humans. Therefore, water treatments that can eliminate toxins are very crucial. Unfortunately, pollution treatment remains a difficulty when four broad considerations are taken into account: effectiveness, reusability, environmental friendliness, and affordability. In this situation, protecting water from contamination or creating affordable remedial techniques has become a serious issue. Although traditional wastewater treatment technologies have existed since antiquity, they are both expensive and inefficient. Nowadays, advanced sustainable technical approaches are being created to replace traditional wastewater treatment processes. The present study reviews the sources, toxicity, and possible remediation techniques of the water contaminants.

Exploration of Whole Blood Chromium as Biomarker of Hexavalent Chromium Exposure: Based on Literature Review and Monte Carlo Simulation

Hexavalent chromium (Cr(VI)) is a sort of common industrial poison and environmental pollutant posing great health threat to the population. Appropriate biomarkers are indispensable indicative tools in the biological monitoring and health risk assessment of Cr(VI). In this study, we explored the rationality and feasibility of whole blood Cr serving as the biomarker of internal exposure with corroboration drawn from literature review and Monte Carlo simulation. It was indicated that the whole blood Cr had practical operability in the large-scale population researches and robust biological significance with broad association with various Cr(VI)-related effect indices. The simulated distribution of whole blood Cr concentration in exposed populations was about three times higher than that of the control (13.52 ± 24.99 vs. 4.25 ± 11.37 μg/L, P < 0.05; 6.73 ± 10.92 μg/L vs. 1.96 ± 2.05 μg/L in China, P < 0.05), which suggested a great discriminatory ability that might be supported as evidence for its reasonable application.

Occupational exposure to hexavalent chromium. Part I. Hazard assessment of non-cancer health effects

Hexavalent chromium (Cr(VI)) compounds have been studied extensively and several agencies have described their toxicological profile. In the past, personnel of the Dutch Ministry of Defence may have been exposed to Cr(VI) during maintenance activities. To investigate if this exposure may have caused irreversible adverse health effects, the Dutch National Institute for Public Health and the Environment (RIVM) summarized all available knowledge from previous evaluations. This information was complemented with a scoping review to retrieve new scientific literature. All scientific evidence was evaluated in workshops with external experts to come to an overview of irreversible adverse health effects that could be caused by occupational exposure to Cr(VI) compounds. This review focuses on non-cancer health effects. It was concluded that occupational exposure to Cr(VI) can cause perforation of the nasal septum by chromium ulcers, chronic lung diseases, including asthma, rhinitis, pulmonary fibrosis and COPD, skin ulcers and allergic contact dermatitis in humans. It is currently insufficiently clear if Cr(VI) can cause irreversible diseases due to disturbances of the immune system (other than allergic contact eczema, allergic asthma and rhinitis and chronic lung diseases) or adverse effects on fertility or prenatal development in humans.

Subchronic Arsenism Disorders mRNA Expression of Cytokines and Immunoglobulins in the Intestinal Tract of the Cock

Provision of feed containing arsenic may cause intestinal flora imbalance and consequently, the dysfunction of immunological protection of the cock. To understand the intricate tuning of immune responses in the intestinal tract elicited by subchronic arsenism, a cock model (1-day-old Hy-line cocks) was established by subjecting cocks to different environmentally relevant concentrations of arsenic in the diet for 90 days. Intestinal cytokine and immunoglobulin (Ig) messenger RNA (mRNA) expression levels were determined using real-time PCR on days 30, 60, and 90. Results showed that, compared to those of the control groups, the mRNA levels of interleukin (IL)-1β, IL-2, IL-4, and interferon (IFN)-γ displayed increases on day 30 then decreases on days 60 and 90 dose-dependently in every tissue. Except for the decrease in the jejunum, the mRNA levels of IL-6 and IL-8 were increased in the duodenum, ileum, cecum, and rectum. However, the mRNA levels of IL-12β decreased in every tissue and every time point compared to those of the control groups. In contrast, chicks showed considerably higher expression levels of IgA, IgM, and IgG after exposure to arsenic. These results demonstrated that immune strategies of cocks were disturbed when suffered from subchronic arsenism, at least on the intestinal level.

Toxicity and oxidative stress induced by chromium in workers exposed from different occupational settings around the globe: A review

The present review focused on the levels and toxicological status of heavy metals especially chromium (Cr) in the exposed workers from different occupational settings around the globe and in Pakistan. It was found that exposed workers from leather tanning and metal plating units showed elevated levels of Cr than the workers from other occupational settings. Cr and other heavy metals level in biological matrices of the exposed workers in different occupational settings revealed that developing countries are severely contaminated. Occupational settings from the Sialkot district, Pakistan exhibited elevated level of Cr in biological entities of the exposed workers. Review suggested that higher level of Cr exposure to the workers enhance the oxidative stress (reactive oxygen species (ROS) and hydroxyl (OH) radical generation) which may cause; cellular and molecular damage such as genotoxicity and chromosomal aberration formations, and carcinogenic effects. This review will help to understand the Cr contamination mechanisms and associated health implications in different occupational settings around the globe in general and particularly to Pakistan. This study will also assist occupational health and safety management authorities to devise or change the Cr recommended exposure limits (REL) for different occupational settings.

Chromium exposure among children from an electronic waste recycling town of China

Guiyu is one of the most heavily chromium-polluted areas in China due to the numerous informal electronic waste (e-waste) recycling activities. A 3-year (2004, 2006, and 2008) independent cross-sectional study on blood chromium (BCr) levels of 711 children from Guiyu and a control area was investigated. Questionnaire completed by parents/guardians was used to assess the risk factors of chromium (Cr) exposure, while physical examination, for the year 2008 only, was used to evaluate the effects of long-term exposure to Cr on child physical development. Children living in Guiyu had significantly higher BCr levels compared with those living in Chendian at the same period from 2004 to 2008 (P < 0.001). The predominant risk factors related to elevated child BCr levels included the use of house as a family workshop, parent involved in e-waste recycling, and child residence in Guiyu. Children's weight and chest circumferences in group with high exposure to Cr (upper quartile) were higher than in the low-exposure group (P < 0.01), although the difference was less significant for boys between the two groups (P < 0.05). The results suggest that elevated child BCr in Guiyu due to informal e-waste recycling activities might be threatening the health of children, with implications on physical growth and development.

Assessing the suitability of 8-OHdG and micronuclei as genotoxic biomarkers in chromate-exposed workers: a cross-sectional study

OBJECTIVES

We aimed to investigate suitable conditions of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and micronucleus (MN) as genotoxic biomarkers at different levels of occupational chromate exposure.

DESIGN

A cross-sectional study was used.

PARTICIPANTS

84 workers who were exposed to chromate for at least 1 year were chosen as the chromate exposed group, while 30 non-exposed individuals were used as controls.

MAIN OUTCOME MEASURES

Environmental and biological exposure to chromate was respectively assessed by measuring the concentration of chromate in the air (CrA) and blood (CrB) by inductively coupled plasma mass spectrometer (ICP-MS) in all participants. MN indicators, including micronucleus cell count (MNCC), micro-nucleus count (MNC), nuclear bridge (NPB) and nuclear bud (NBUD) were calculated by the cytokinesis-block micronucleus test (CBMN), while the urinary 8-OHdG was measured by the ELISA method and normalised by the concentration of Cre.

RESULTS

Compared with the control group, the levels of CrA, CrB, MNCC, MNC and 8-OHdG in the chromate-exposed group were all significantly higher (p<0.05). There were positive correlations between log(8-OHdG) and LnMNCC or LnMNC (r=0.377 and 0.362). The levels of LnMNCC, LnMNC and log (8-OHdG) all have parabola correlations with the concentration of CrB. However, there was a significantly positive correlation between log (8-OHdG) and CrB when the CrB level was below 10.50 µg/L (r=0.355), while a positive correlation was also found between LnMNCC or LnMNC and CrB when the CrB level was lower than 9.10 µg/L (r=0.365 and 0.269, respectively).

CONCLUSIONS

MN and 8-OHdG can be used as genotoxic biomarkers in the chromate-exposed group, but it is only when CrB levels are lower than 9.10 and 10.50 µg/L, respectively, that they can accurately reflect the degree of genetic damage.

Alteration of Th1/Th2/Th17 cytokine profile and humoral immune responses associated with chromate exposure

BACKGROUND

The role of chromate exposure in the deregulation of total lymphocyte and other immune factors is largely unclear.

OBJECTIVES

We aimed to examine alteration of the Th1/Th2/Th17 cytokine profile and humoral indicators caused by occupational chromate exposure.

METHODS

A cross-sectional study was conducted in two similar workshops (groups 1 and 2) with 106 male occupational workers and 50 matched local controls. Environmental and biological exposures were assessed by measuring chromium concentrations in workplace air, and in whole blood and urine samples of the workers. Cytokines in serum (IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ, IL-17A) were determined by CBA assay, while immunoglobin (IgA, IgM, IgG, IgE) and complement (C3, C4) were evaluated by immunonephelometric and ELISA methods. Micronucleus analysis was also used to explore the relationship between genotoxicity and immunotoxicity.

RESULTS

Compared with the control group, environmental chromate exposure in groups 1 and 2 was much higher, and the mean values of IL-6, IL-10, IFN-γ, IL-17A and IFN-γ/IL-4 were significantly decreased in group 1. In group 2, IgA and IgG levels were reduced, while C3 and C4 were increased. Levels of IFN-γ, IgG and IgA were all inversely associated with whole blood chromium, while C3 and C4 were positively associated with whole blood chromium (p<0.05). Both IL-10 and IL-17A were inversely associated with urine chromium. Correlations were also found between IL-10, IL-17A and micronucleus (r=-0.329, r=-0.312, respectively).

CONCLUSIONS

Occupational exposure to chromate could downregulate the cellular and humoral factors of the immune system.