changing work exposures, it may be possible to reliably discern a causal relationship. Furthermore, some of these reports included individual experiments in which subjects were exposed to CCP or its components and objective signs and symptoms were evaluated following these exposures. These studies can provide stronger evidence for causality than ordinary case reports that are based on subjective reports of past experiences.
Table 4-1 lists 39 currently available, published case reports and case series related to CCP, including a number of series assembled in NIOSH Health Hazard Evaluations (investigations conducted under the authority of the Occupational Safety and Health Act of 1970 [29 USC[1] 1900]). Nine reports provided information about the experience of a single worker. In the case series, ranging from 2 to 276 workers, symptoms were generally clustered within a defined period and involved a number of employees at a single workplace, often situated in a single room or activity. The observed symptoms varied considerably from site to site, but most included skin problems such as itching, rash, dryness, and eczema as well as mucous membrane irritation, particularly of the eyes, mouth, nose, and throat. Lower respiratory problems were less frequent. Headache was also reported as a problem (to a smaller extent), and fatigue was also mentioned.
The following are summaries of the studies outlined in Table 4-1.
Magnusson 1974. Magnusson [1974] conducted his investigation in Sweden at a workplace where 15 of 18 women working with CCP had reported itching and dryness of the skin, lips, tip of nose, and eyes as well as burning sensations or dryness in the mouth. The symptoms mostly appeared a few weeks after the first exposure to CCP. Seven of the 15 women showing symptoms were skin-patch tested using the paper in question and a standard series. All tests were negative but one, which showed reaction to nickel and cobalt. Symptoms disappeared after introduction of a new type of paper containing a resin to bind the clay material.
Hannuksela 1975. A report by Hannuksela [1975] (unavailable to NIOSH but cited by Jeansson et al. [1983]) found 20 workers among several hundred in a Swedish bank who suspected that eczema on their hands was caused by contact with CCP. None of the 19 workers who were skin-patch tested with a CCP bottom sheet emulsion showed an allergic reaction. One later case was reported as positive, with most of the complaints attributed to physical factors (such as abrasiveness) related to CCP.
Wahlberg 1975. In a personal communication reported by Jeansson et al. [1983], Wahlberg found the CCP-related problems to be relatively evenly distributed between two main types of CCP used in Sweden at the time—clay- and polymer-based papers. He suggested that a finely distributed dust arising from leafing through and tearing the paper was a likely explanation of the symptoms.
Hirvonen et al. 1976. Hirvonen et al. [1976] obtained positive skin-patch test reactions for irritation in 4 of 32 cases associated with CCP from a total of 1,050 cases of occupational dermatitis in Sweden during the period 1973 to 1976. In all four cases, the rash began in areas typical of paper contact—the finger tips of one or both hands and the outer edges of the hand. The eyelids of one worker also revealed a rash. Of the four patients, two reacted only to the top side of the paper but not to the CB or CF portions. Two patients reacted to all of the
- ↑ United States Code. See USC in references.
