# Comment on “Association between Residential Proximity to Viticultural Areas and Childhood Acute Leukemia Risk in Mainland France: GEOCAP Case-Control Study, 2006–2013”

Catherine Hill¹

¹Institut Gustave Roussy, Villejuif, France

https://doi.org/10.1289/EHP14230

Refers to https://doi.org/10.1289/EHP12634

Mancini et al. compared the place of residence of 3,711 patients under 16 years of age diagnosed with primary acute leukemia between 2006 and 2013 to the place of residence of a control population of 40,196 children.¹ The proportion of acute leukemia cases living within 1,000 m of viticultural areas was not larger than the proportion of controls; it was actually slightly smaller [9.4% vs. 10%; odds ratio (OR) = 0.86 adjusted on age]. Restricting the study to the 3,088 cases of acute lymphoblastic leukemia led to an age-adjusted OR of 0.90.

The authors also estimated an OR varying with the density of vines within 1,000 m of the place of residence, assuming a linear increase in the logarithm of the odds with an increasing density of vines. They reported an OR of 1.05 for a 10% increase in density. The authors accept this overall estimation despite the inconsistency of the results by regions, which varied from a 44% risk reduction in Auvergne-Rhône Alpes to a 21% increase in Pays de la Loire.

The authors reported the distributions of the cases and controls by deciles of vine density, but only for the Occitanie region (Table 1), not for the overall results and adjusted ORs. These data illustrate the fact that when the risk associated with any density of vines is <1, a linear increase of the OR with the density of vines implies an OR clearly <1 for a low density of vines, and >1 only for very

<table><caption>**Table 1.** Association between the density of viticulture and the risk of acute lymphoblastic leukemia in the Occitanie region.</caption><thead><tr><th>Line index</th><th>Median viticulture density (%)<sup>a</sup></th><th>Cases (a<sub>i</sub>) (n)<sup>a</sup></th><th>Controls (c<sub>i</sub>) (n)<sup>a</sup></th><th>OR<sup>b</sup></th></tr></thead><tbody><tr><td>0</td><td>0</td><td>163</td><td>2,008</td><td>1</td></tr><tr><td>1</td><td>0.10</td><td>6</td><td>125</td><td>0.58</td></tr><tr><td>2</td><td>0.80</td><td>3</td><td>128</td><td>0.28</td></tr><tr><td>3</td><td>2.20</td><td>9</td><td>122</td><td>0.90</td></tr><tr><td>4</td><td>4.90</td><td>6</td><td>124</td><td>0.58</td></tr><tr><td>5</td><td>10.3</td><td>7</td><td>123</td><td>0.69</td></tr><tr><td>6</td><td>17.3</td><td>12</td><td>118</td><td>1.27</td></tr><tr><td>7</td><td>25.6</td><td>7</td><td>123</td><td>0.69</td></tr><tr><td>8</td><td>34.0</td><td>8</td><td>122</td><td>0.80</td></tr><tr><td>9</td><td>44.5</td><td>20</td><td>110</td><td>2.41</td></tr><tr><td>10</td><td>60.2</td><td>10</td><td>120</td><td>1.03</td></tr><tr><td>Total</td><td>—</td><td>251</td><td>3,223</td><td>—</td></tr><tr><td>Sum 1 to 10</td><td>Any density</td><td>88</td><td>1,215</td><td>0.77</td></tr></tbody></table>

Note: —, not applicable; OR, odds ratio.

<sup>a</sup>Data from the first three columns of Table S4 in Mancini et al.¹

<sup>b</sup>ORs estimated as $\frac{a_i(c_i - c_i)}{c_i(a_i - a_i)}$.

<figure><img src="image_1.png" /><figcaption>**Figure 1.** Odds ratio as a function of viticulture density; data from Table 1.</figcaption></figure>

high density of vines (Figure 1). This shows that living close to some vines is associated with a reduced risk of pediatric acute lymphoblastic leukemia as compared to living close to no vines and that only a place of residence close to a very high density of vines is associated with a small increase in risk.

Can the authors clarify what is represented by the vertical axis of Figure S4 scaled from -4 to 0? This vertical axis is labeled β, but the values $exp(βd)$ do not seem compatible with the ORs presented.

The results of this study are not convincing. They are inconsistent between regions, and the overall result defies logic. This does not justify the alarming information distributed by the media in France.

## Reference

1. Mancini M, Hémon D, de Crouy-Chanel P, Guldner L, Faure L, Clavel J, et al. 2023. Association between residential proximity to viticultural areas and childhood acute leukemia risk in mainland France: GEOCAP case-control study, 2006–2013. Environ Health Perspect 131(10):107008, PMID: 37850750, https://doi.org/10.1289/EHP12634.

Address correspondence to Catherine Hill. Email: Catherine.hill@gustaveroussy.fr

The author declares she has no conflicts of interest related to this work to disclose.

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