The NPIS Pesticide Surveillance Project - Eye contact with pesticides: circumstances of exposure and toxicity

Objective: Neonicotinoids are a relatively new class of insecticide about which there is limited information on human toxicity in Europe. We describe neonicotinoid exposures during 8 years of the National Poisons Information Service (NPIS) Pesticide Surveillance Project and compare poisoning severity against other more established insecticides in use in the UK.

Methods: The NPIS monitors and follows up pesticide exposures following Internet (TOXBASE^®) or telephone enquiry. Poisoning severity scores (PSS) for neonicotinoids were compared against other insecticides in similar categories of use. Categories of use: professional/amateur, agriculture, veterinary, fly-killer, ant-killer, other insecticide.

Results: 105 unintentional neonicotinoid exposures were reported. Seventy-four imidacloprid (28 in combination with moxidectin, 19 methiocarb, 7 permethrin, 1 beta-cyfluthrin); 24 nitenpyram; 4 acetamprid; 3 thiacloprid. Fifty-three adults and 52 children; 55 female, 50 male. Most exposures (103) were acute. Route: ingestion (61); inhalation (11); skin contact (11); eye contact (5); multiple routes (16); NK (1). Thirty-one exposures occurred during patient use, 11 by another person, 21 after application, 21 unsatisfactory storage. Volumes involved are likely to be small, data is limited. Common symptoms: nausea/vomiting (7); eye irritation (6); skin irritation (5); diarrhoea (4); mouth/throat irritation (4); mouth paraesthesia (3); skin paraesthesia (3); dyspnoea (3). Neonicotinoids were reported mainly in two categories: veterinary domestic use (71) and amateur “other insecticide” (28). Amateur “other insecticide” PSS - Neonicotinoids: none 18 (64.3%); minor 10 (35.7%); moderate 0; uncertain 0. Pyrethroids: none 98 (37.8%); minor 139 (53.7%); moderate 15 (5.8%); uncertain 7 (2.7%). Carbamates: none 12 (48.0%); minor 11 (44.0%); moderate 1 (4.0%); uncertain (4.0%). Other (not OP): minor 13 (40.6%); minor 17 (53.1%); moderate 2 (6.3%); uncertain 0. (P = 0.046). Veterinary domestic PSS - Neonicotinoids: none 48 (67.6%); minor 22 (31.0%); moderate 1 (1.4%); uncertain 0. Pyrethroids: none 64 (57.1%); minor 47 (41.9%); moderate 0; uncertain 1 (0.9%). Other (not OP): none 39 (56.5%); minor 26 (37.7%); 4 moderate (5.8%); uncertain 0. (P = 0.285).

Conclusion: In the UK unintentional domestic exposures to neonicotinoids are of low toxicity. For amateur home/garden insecticides severity was significantly lower than other agent classes (P = 0.046). Toxicity may differ in other parts of the world or self-harm where larger volumes are involved.