Systematic review of the literature on triclosan and health outcomes in humans

Abstract

The ability of epidemiologic evidence to inform regulatory decisions is largely dependent on the coherence and quality of the published literature. This systematic review examines the quality and consistency of studies assessing health outcomes associated with exposure to triclosan (TCS), an antimicrobial chemical with a short physiologic half-life. We used elements of the Biomonitoring, Environmental Epidemiology, and Short-Lived Chemicals instrument to evaluate aspects of study quality. Each methodological domain -overall design, exposure assessment, and data analysis -was categorized according to three tiers where Tier 1 indicated the highest quality. We also examined consistency of methods, results and reporting as considerations for weight of evidence (WOE) assessment. Studies were considered sufficiently comparable if they addressed the same or similar research questions. Forty-two studies met the criteria for inclusion. Only one randomized cross-over clinical trial of TCS was assigned to Tier 1 for all three domains. Most other studies were assigned to Tier 3 for at least one domain. Although the available literature examined more than 100 different health endpoints and reported hundreds of different measures of association, few studies were considered comparable. For reported measures of association, most were not significantly different from the null; the few statistically significant results represented isolated findings without a discernable across-or within-study pattern. We conclude that the current body of epidemiologic literature does not allow a meaningful WOE assessment due to methodological limitations of individual studies and lack of inter-study consistency. On the other hand, methodologically stronger studies may be used to inform future research. ARTICLE HISTORY

Evidence of the Possible Harm of Endocrine-Disrupting Chemicals in Humans: Ongoing Debates and Key Issues

“…For example, reviews of the effects of bisphenol A (BPA) in humans reported conflicting results with respect to pubertal development [ 22 ] and diabetes [ 23 ]. Similar conclusions have been reached on phthalate and obesity [ 24 ], triclosan and diverse health effects [ 25 ], and developmental exposure to many EDCs and male reproductive disorders [ 26 ].…”

The Effects of Dry, Humid and Wear Conditions on the Antimicrobial Efficiency of Triclosan-Containing Surfaces

“…However, these adverse results on human health after exposure to triclosan are not yet clear [61]. Goodman et al [62] observed that the health problems attributed to triclosan are not necessarily being produced exclusively by this agent and can also be attributed to other chemical products with similar properties. In real usage, triclosan is not expected to cause health effects when products containing this agent are used according to indications [21].…”

Embracing microbes in exposure science

“…Scientific understanding of health risks associated with triclosan as an environmental chemical is still developing. In a recent review, Goodman et al [88] concluded that "the current body of epidemiologic literature does not allow a meaningful weight of evidence assessment due to the methodological limitations of individual studies and lack of inter-study consistency." Evidence for concern is accumulating, however.…”