Toxicologic, pathologic, and immunotoxic effects of 2,4‐dichlorophenol in rats

Abstract

2,4-Dichlorophenol (DCP) is a drinking and waste-water contaminant formed by the spontaneous reaction of chlorine with phenols following chlorination of water for disinfection and deodorization. Rats were exposed to 0, 3, 30, or 300 ppm DCP in drinking water either in utero or for 12 wk postnatally following in utero exposure. Toxicity to DCP was assessed by organ and body weight changes, histopathology, and effects on reproduction and immunocompetence. Reproductive parameters measured included conception, litter size, pup birth weight, number stillborn, survival to weaning, and weaning weight. Immune parameters assessed were humoral immunity (antibody production) by an indirect enzyme-linked immunosorbent assay (ELISA), cell-mediated immunity by a delayed-type hypersensitivity response, and macrophage function by phagocytosis of radiolabeled blood cells. Rats that received the combined in utero and postnatal treatment with 300 ppm DCP had significantly increased liver and spleen weights, enhanced humoral immune responsiveness, and depressed cell-mediated immunity. Histopathologic changes were unremarkable in DCP-exposed rats, even in the presence of increased liver and spleen weights. The 6-wk-old progeny of DCP-treated dams had normal immune functions and showed no signs of DCP toxicity, other than increased spleen weights in the 300-ppm exposure group. The results indicate that (1) the immune system may be a sensitive target for chlorinated phenolic compounds, (2) DCP may exert different effects on separate major immune responses, and (3) unlike some other chlorinated phenols, DCP does not appear to alter reproductive performance in rats.

Concentrations of environmental phenols and parabens in milk, urine and serum of lactating North Carolina women

“…2,5-dichlorophenol, the primary metabolite of p-dichlorobenzene, is common in US populations [1]. Exposure to high doses of 2,4-chlorophenol in laboratory animals causes immunological and liver related effects, in addition to smaller litters and offspring with decreased birth weight [48]. There are a couple of technical manuscripts devoted to analytical method development that report rarely detecting 2,4- and 2,5-dichlorophenol in milk [39, 49].…”

Association of urinary triclosan, methyl triclosan, triclocarban, and 2,4-dichlorophenol levels with anthropometric and demographic parameters in children and adolescents in 2020 (case study: Kerman, Iran)

“…2,4-DCP is a lipophilic chlorinated phenol from the phenoxy acetic acid herbicide family that is frequently utilized in the production of herbicides and insecticides (Exon et al 1984;Magnoli et al 2020;Zhang et al 2018). Excessive doses of herbicides are frequently employed due to weed resistance, resulting in biological buildup even with shortterm exposure (Magnoli et al 2020).…”

“…2,4-DCP can be generated by the deformation of pesticides, primarily phenoxy herbicides like 2,4-dichlorophenoxyacetic acid, as well as antibacterial and antifungal chemicals like triclosan, which is also a byproduct of municipal drinking water and industrial effluent chlorination (Bukowska et al 2016;Ye et al 2014). Because of these chemicals' lipophilic characteristics, if they reach the environment, they can accumulate in the bodies of plants and animals, eventually entering the food chain and endangering health (Ding et al 2020;Exon et al 1984;Yueh and Tukey 2016;Parastar et al 2018).…”

A Two-Generation Reproductive Toxicity Study of 2,4-Dichlorophenol in Rats

“…It has also been reported that 2,4-DCP can be formed as a degradation product of 2,4-D (Zona et al, 2002) and that phenols and chlorines may naturally react with each other to form 2,4-DCP on disinfection of drinking water or with deodorization of pollutant water (Exon et al, 1984).…”