AEROALLERGENS AND HYMENOPTERA

House dust and storage mite contamination of dry dog food stored in open bags and sealed boxes in 10 domestic households

Dry pet food is a potential source of exposure to house dust and storage mite allergens in canine atopic dermatitis. This study evaluated contamination of house dust and dry dog food stored in paper bags, sealable plastic bags and sealable plastic boxes in 10 households for 90 days using Acarex(®) tests for guanine, a Der p 1 ELISA and mite flotation. Acarex(®) tests were negative in all the food samples but positive in all the house dust samples. The Der p 1 levels and mite numbers significantly increased in food from paper bags (P = 0.0073 and P = 0.02, respectively), but not plastic bags or boxes. Mite numbers and Der p 1 levels were 10-1000 times higher in house dust than the corresponding food samples (P < 0.0001). There were significant correlations between Der p 1 in house dust and food from the paper (P < 0.0001) and plastic bags (P = 0.003), and mite numbers in house dust and food from the paper bags (P = 0.0007). Bedding and carpets were significantly associated with Der p 1 levels in house dust (P = 0.015 and P = 0.01, respectively), and food from the paper (both P = 0.02) and plastic bags (P = 0.03 and P = 0.04, respectively). Mites were identified in six of 10 paper bag, three of 10 plastic bag, one of 10 plastic box and nine of 10 house dust samples. These comprised Dermatophagoides (54%), Tyrophagus (10%; all from food) and unidentified mites (36%). Storage of food in sealable plastic boxes largely prevented contamination for 3 months. Exposure to mites and mite proteins in all the stored food, however, appeared to be trivial compared with house dust.

A comparative, volumetric survey of airborne pollen in Philadelphia, Pennsylvania (1991-1997) and Cherry Hill, New Jersey (1995-1997)

BACKGROUND

Aeroallergen sampling provides information regarding the onset, duration, and severity of the pollen season that clinicians use to guide allergen selection for skin testing and treatment.

OBJECTIVE

This atmospheric survey reports: 1) airborne pollen contributors in Philadelphia, Pennsylvania (1991 to 1997) and suburban Cherry Hill, New Jersey (1995 to 1997); 2) pollen onset, duration, and peak level; and 3) the relationship between airborne pollen and selected meteorologic variables.

METHODS

At both locations, separated by 11 km. sampling was performed with a volumetric Rotorod Sampler (Sampling Technologies, Minnetonka, MN).

RESULTS

In Philadelphia and Cherry Hill, respectively, 3-year average measurements included 75.0 and 74.2% tree pollen, 10.2 and 8.3% grass pollen, and 14.8 and 17.5% weed pollen. Prominent airborne pollen taxa were Acer, Quercus, Betula, Pinus, Cupressaceae, Poaceae, Ambrosia, and Rumex. The tree, grass, and weed pollen seasons extended from mid-March to mid-June, late April to mid-June, and mid-August to late September, respectively. A secondary Poaceae pollen peak occurred in September. There was a statistically significant correlation between simultaneous weekly average pollen levels in Philadelphia and in Cherry Hill (Acer, r(p) = 0.987, Quercus, r(p) = 0.645, Betula, r(p) = 0.896, Pinus, r(p) = 0.732, Cupressaceae, r(p) = 0.695, Poaceae, r(p) = 0.950, Ambrosia, r(p) = 0.903, and Rumex, r(p) = 0.572, P <0.001). Daily Poaceae pollen levels were positively influenced by same-day high temperature (r(s) = 0.333 in Philadelphia and r(s) = 0.426 in Cherry Hill, P < 0.05). Daily Ambrosia pollen levels were inversely influenced by same-day total precipitation (r(s) = -0.174 in Philadelphia and r(s) = -0.257 in Cherry Hill, P < 0.05).

CONCLUSIONS

This is the first volumetric survey performed in either Philadelphia or Cherry Hill. Copious amounts of airborne pollen were seen from late April to early May and in early September. Pollen onset, duration, and year-to-year variability were similar at both sites. An awareness of local aeroallergen patterns is critical in the effective testing and treatment of atopic individuals.