agricultural activities could influence the risk of ALS, with occupational exposure to agricultural chemicals playing a possible role.



Amyotrophic lateral sclerosis, rural environment and agricultural work
in the Local Health District of Ferrara, Italy, in the years
1964-1998
V. Govoni1 , E. Granieri1, E. Fallica2 and I. Casetta1

(1) Sezione di Clinica Neurologica, Dipartimento di Discipline
Medico-Chirurgiche della Comunicazione e del Comportamento
Università di Ferrara, Corso della Giovecca, 203, 44100 Ferrara, Italy

(2) Neurological Unit, S. Anna Hospital of Ferrara, Ferrara, Italy

Received: 23 December 2004 Revised: 21 February 2005 Accepted: 23
February 2005 Published online: 5 July 2005

Abstract Previous epidemiological surveys, both analytic and
descriptive, in the Local Health District (LHD) of Ferrara, northern
Italy, have indicated that rural residence and agricultural work might
constitute risk factors for Amyotrophic Lateral Sclerosis (ALS). The
present investigation is a demographic survey in the LHD of Ferrara in
the years 1964-1998 which aimed to verify whether the level of
urbanization and agricultural activities might influence the risk of
ALS. Based on the data obtained in a recent incidence study in the LHD
of Ferrara which reported a mean annual crude incidence rate of ALS in
the years 1964-1998 of 1.63 per 100,000 population (95 % CI
1.31-2.00), it was possible to compare the number of observed ALS
cases and the number of expected ALS cases according to the level of
urbanization and usual occupation on the basis of the residential and
occupational pattern identified in the population of the LHD of Ferrara
in the study period under the assumption of a homogeneous distribution
of ALS. The present survey identified four different levels of
urbanization in the LHD of Ferrara in the study period and for none of
them was a difference between the number of observed and expected ALS
cases found. Also in the most rural of the four identified levels of
urbanization (small villages with an average population in the study
period lower than 1,000 inhabitants and scattered houses in the
countryside) no difference was found between observed and expected
number of ALS cases (observed ALS cases 16, 95% Poisson CI 9.1-25.9,
expected ALS cases 18.3). Based on the occupational pattern identified
in the population of the LHD of Ferrara in the study period the number
of incident cases of ALS whose usual occupation was in agricultural
work exceeded the expected number (observed ALS cases 22, 95% Poisson
CI 13.8-32.3, expected ALS cases 6.0). The present findings indicate
that rural residence itself does not influence the risk of ALS while
agricultural activities could influence the risk of ALS, with
occupational exposure to agricultural chemicals playing a possible
role.
Key words amyotrophic lateral sclerosis - incidence - rural residence
- agricultural work


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V. Govoni
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Phone: +39-0532/236304
Fax: +39-0532/205525

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