Crop flowering

Exploring crop flowering's impact on allergies

Agriculture in the Negev has significantly contributed to the region's development and economy despite its arid climate. Major crops include olives, dates, pomegranates, and grapes, cultivated using modern, sustainable methods. Additionally, innovative projects like greenhouse vegetable farming are present. While agriculture has been prominent in the Negev for decades, the health implications for local residents, particularly regarding allergic airway disease (AAD), remain underexplored. International studies indicate that grass pollens and other crop-related airborne allergens are significant triggers for AAD, affecting 5-30% of the population in industrialized nations. However, research has mainly focused on farm workers rather than the surrounding residents.

The Negev's meteorological conditions, such as higher temperatures, high wind speeds, and low humidity, facilitate increased pollen release. Given the expected rise in AAD and pollen-related allergy attacks due to climate change, this study aims to investigate the association between crop blooms and allergy season in the Negev.

We hypothesize a temporal association between crop (and other plant) blooming and higher rates of allergy-related emergency department (ED) visits and allergy medication purchases.

Study Objectives

1. Create a spatial and temporal layer of exposure to crop and plant-related allergens.
2. Estimate the prevalence of allergy attacks in the Negev.
3. Examine the association between temporal and geographic proximity to agriculture and allergy attacks.

Study Population

The study will include all Clalit Health Services members residing in the Southern District of Israel from 2001 to 2022. The population encompasses all age groups to account for medical conditions among both adults and the pediatric population.

Study Design

The prevalence of allergy attacks in the Negev during the study period will be estimated by searching Soroka University Medical Center (SUMC) medical records for allergy-related ED visits and purchases of allergy medications from Clalit pharmacies. Severe cases will also consider allergy-related hospitalizations.

Population exposure to crop-related allergens will be assessed by examining the seasonal blooming peaks of various crops in the Negev over the study period. These peaks will be compared to peaks in allergy attacks. The impact of proximity to agriculture on allergy incidences will be analyzed by mapping subjects' residence coordinates against agricultural locations.

Statistical Analysis

Two main methods will be employed:

1. Time-Series Analysis: This will involve recording the seasonal bloom of different crops and comparing these peaks against trends in ED admissions for allergy attacks and allergy medication purchases over time. Long-term correlations will be examined over the 20-year period.

2. Case-Crossover Analysis: This method will estimate the contribution of exposure to crop-related allergens to allergy attacks. The level of exposure during the "hazard" period preceding an allergy attack will be compared to the baseline level of exposure. The hazard period will be estimated based on the average time between exposure and allergy attack.

Limitations

Exposure to crop-related allergens will be approximated using crop blooming cycles and geographic proximity to agriculture, with residence location as a proxy. However, individual exposure may vary due to factors like work location and recreational activities. Additionally, the study assumes peak bloom correlates with peak allergen levels, as direct measurement of airborne allergen levels is not currently planned.