Limonene health effects

Although these reactions result in an increased respirable aerosol mass, little is known about human health effects associated with these particular condensed reaction products. Tamas et al. (2006) observed a correlation between the number concentration of SOAs, from the limonene-ozone reaction in an office, and sensory load reported by 20 human subjects. Additionally, a screening study indicates that perfume wearers will be subjected to a personal reactive cloud of reaction products, such as fine aerosols (Corsi et al., 2007). 

Importance of Limonene in the Human Diet—Health Effects.180... 

IMPORTANCE OF LIMONENE IN THE HUMAN DIET —HEALTH EFFECTS... 

Relevant threshold limit values for terpenes are rare because of a lack of basic information about specific terpene products and by-products on the one hand, and occupational and environmental exposures on the other hand. The threshold limit values which have been documented the best concern oil of turpentine. A MAK-value of 100 ppm is defined in German regulations and noted to be dermally sensitive. For other terpenes, such as d-limonene which is also classified as dermally sensitive, it has not yet been possible to establish a MAK-value because of a lack of information of their effects on animals or humans. With terpenes, as is often the case, aggregate concentration parameters are used as limit values such as the minimum level goals recommended by the former German Federal Health Authority. These suggested minimum values bear in mind actual levels detected in indoor areas. 

In the industry of insecticides, one of the central issues is to develop products that are not harmful to the environment and to human health. It has been shown that a-pinene, camphor and limonene can be good natural repellents for insects [155]. Besides the use of geraniol in the industry of fragrances, this compoxmd has also proven effective as a mosquito repellent [156, 157]. Terpene halides, 3-carene, and toxaphene, a chlorinated camphene, are important for agriculture because of their use as pesticides [158, 159]. However, especially for toxaphene, several restriction issues have been raised because of its pollutant capacity and carcinogenic potential in humans [159-161]. 

The National Institute of Environmental Health Sciences [39] studied myrcene for its cancerogenic activity, because it is heavily produced and shows structural connections to limonene, which induces tumors in male rat kidneys. The study was performed on male and female rats and mice by force-feeding with myrcene for either 3 months or 2 years. The results of the 2-year studies showed that myrcene possesses a carcinogenic effect based on increased incidence of renal tubule neoplasms in male rats and renal tubule adenomas in female rats. Increased incidence of hepatocellular adenoma, hepatocellular carcinoma, and hepatoblastoma was seen in male mice and marginally increased incidences hepatocellular adenoma and carcinoma were observed in female mice. 

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