Influence of occupational exposure to white board marker ink on symptoms of allergic conjunctivitis among secondary school teachers in Nakuru County, Kenya

Abstract

Allergic conjunctivitis is a common problem affecting about 20% of the world’s population. In Kenya, it constitutes one fifth of all the total diagnoses made in eye clinics with school teachers in Nakuru North Sub-County in Nakuru County having a prevalence of 51.2%. Untreated allergic conjunctivitis can cause injury to the conjunctiva and the eye lids while some of the drugs used to treat can cause life threatening diseases. Irritants such as the volatile organic compounds which constitute the ink solvents of whiteboard marker pens increase the likelihood of developing the allergy. This study therefore sought to establish the influence of the VOCs from the whiteboard marker ink on the development of symptoms of allergic conjunctivitis among the teachers in Nakuru County. The research design was Cross Sectional using repeated measures with a sample of 224 secondary school teachers. Only schools which use whiteboards were considered for the study. Questionnaires were used to collect information on the reported symptoms of allergic conjunctivitis among teachers while air samples were collected using transparent polythene bags. Classroom temperature and CO2 were measured using carbon dioxide sensor AZ-0004. Data was collected in July-Aug (2016), Sep-Oct (2016) and Jan-Feb (2017) months of the year. Air samples were analyzed using gas chromatography. Data was analyzed using both descriptive and inferential statistics. The results showed that the marker pen inks used contained methanol, acetone, hexane and ethanol. The ink VOCs were more likely to be found at the upper parts and front of the classrooms. Teachers were not knowledgeable on ink safety but had a positive attitude towards the use of the marker pens. They also did not show safe practices when using the marker pens in classrooms. The concentration of ink VOCs in the air increased with increase in concentration of CO2 and temperature. The highest incidences of symptoms of allergic conjunctivitis were in the cold seasons while the lowest incidence was in the hottest and dry months of the year. Increase in symptoms of allergic conjunctivitis increased with increase in concentration (r2=0.8414) and duration of exposure (r2=0.5807) to ink VOCs while there was a significant association (χ2 =6.933; p=0.031) between ink brand and eye irritation. This study concludes that occupational exposure to whiteboard marker pen ink causes symptoms of allergic conjunctivitis and recommends that teachers be trained on occupational safety procedures on handling whiteboard marker pens in classrooms.