Fibre Toxicology
Laboratory Home Overview:

This laboratory has been engaged in the toxicological studies on particles (including ultrafine) and fibres particularly asbestos. Asbestos is a mining produce and used in the manufacture of about 3000 products. The most common asbestos-based products are the roofing sheets, water supply and drainage pipes, brake-shoes, fire proof clothes etc. Briefly, asbestos became ubiquitous and a matter of concern because of its carcinogenic nature. Laboratory investigated asbestos toxicity using in vitro cell models namely alveolar macrophages and hepatocytes isolated from rat. Mechanistic studies on toxicity of asbestos revealed oxidative stress, enhanced formation of micronuclei and chromosomal aberrations as some of the underlying mechanisms of its toxicity and genotoxicity.

  Major activities:

Main objectives of the laboratory include studies on industrial hygiene particularly in asbestos-based industries and toxicity of fibres and particles including nanoparticles.

Highlights of Current Research:

  • Recently, unorganized asbestos units operating in Rajasthan, the richest State of indigenous asbestos in India, have been the focus of studies relating to industrial hygiene and health risk assessment. Work place asbestos concentration in all the unorganized asbestos mills were many- folds higher than the Indian Standard. Predominant variety of asbestos was tremolite. Exposed population showed higher prevalence of respiratory symptoms, pulmonary impairment and radiological abnormalities. 

  • Another area of recent research has been the environmental health effects of asbestos released in the environment through monitoring of asbestos in various abiotic and biotic (about 100 species of fauna and flora) components of the ecosystems around an asbestos-based industry. Asbestos burden in the similar samples invariably showed gradual reduction with the increasing distance from the asbestos industry. Matching with the field burden, laboratory experiments were also conducted in some ecologically important species. As predators play vital role in the ecological balance, one such species, Nepa anophthalma (predatory aquatic insect, also called as water scorpion) was selected as a test model for asbestos toxicity study. N. anophthalma was found with asbestos burden (Fig 1). This species near the factory site showed enhanced level of lipid peroxidation (LPO) and reduced level of glutathione (GSH) when compared with that of control site. Similarly, studies were extended to earthworm; Foedita sp. Asbestos burden in Foedita (Fig 2) registered a decreasing trend along with the increasing distance from industry. Experimentally, exposure of earthworm to asbestos mimicking to field concentrations produced enhanced LPO, activities of catalase, glutathione peroxidase, and hydrogen peroxide production with concomitant depletion of GSH in a dose- and time-dependent manner. 

  • Another area of ongoing research interest is the health risk assessment studies in bone-based industrial units manufacturing decorative and ornamental items. Industrial hygiene status was assessed through monitoring of airborne concentrations of total suspended particulate matter (TSPM), PM10 and PM2.5. Bone-based units were found with TSPM, PM10 and PM2.5 in range of 2.99-5.36, 0.375-1.126, 0.269-0.482 mg/m3, respectively. The occupational dust prevailing in bone-based units were found cytotoxic. Further studies are in progress. 

  • Current interest of this laboratory is the study on health risk and toxicity of asbestos exposed through talc-based cosmetic powders. Talc is a mining produce and quite often naturally contaminated with asbestos. Since talc is the primary constituent of cosmetic powders, therefore usage of asbestos-contaminated cosmetic products pose a risk of exposure to asbestos fibres as well as talc particles including their fine and ultrafine particles. Several branded samples as well as batches of same brand were analyzed and detected asbestos contamination (Fig 3) in the range of 1.8-15.4%. The initial study encouragingly suggests that asbestos contamination of cosmetic powders is a problem in India. Notably, Indian Drugs and Cosmetic Act remains silent with respect to asbestos standard in such products, namely body powder, face powder and baby powder. Prediction of exposure and adverse health effects of cosmetic powders including their fine and ultrafine particles (asbestos and talc) due to application of such products have been, therefore identified current area of research in this laboratory.


   Fig1: Asbestos fibres within Nepa        Fig 2: Asbestos fibres within Foedita


Fig 3: Different types of asbestos fibres in cosmetic powders.

Major Facilities available:

The laboratory has the expertise and the basic equipments required for toxicological investigation of fibres and particles of occupational and environmental importance. It is also equipped to carry out industrial hygiene studies as per the requirements of asbestos-based industries.

  Staff:
Dr. Iqbal Ahmad, Scientist E-II and Head 
Mr. Mohd. Ashquin, Technical Officer 

Project Staff:
Ms. Huma Siddiqui, Research Assistant 
Mr. M.J. Akhtar, Junior Research Fellow 


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